From 4e27a1e02a11ba36c0f60784bd6dd353af378cbc Mon Sep 17 00:00:00 2001 From: Marius Bancila Date: Wed, 27 Jun 2018 11:26:35 +0300 Subject: [PATCH] added GSL for span implementation --- include/gsl/gsl | 29 + include/gsl/gsl_algorithm | 63 ++ include/gsl/gsl_assert | 145 +++ include/gsl/gsl_byte | 181 +++ include/gsl/gsl_util | 158 +++ include/gsl/multi_span | 2242 +++++++++++++++++++++++++++++++++++++ include/gsl/pointers | 193 ++++ include/gsl/span | 766 +++++++++++++ include/gsl/string_span | 730 ++++++++++++ 9 files changed, 4507 insertions(+) create mode 100644 include/gsl/gsl create mode 100644 include/gsl/gsl_algorithm create mode 100644 include/gsl/gsl_assert create mode 100644 include/gsl/gsl_byte create mode 100644 include/gsl/gsl_util create mode 100644 include/gsl/multi_span create mode 100644 include/gsl/pointers create mode 100644 include/gsl/span create mode 100644 include/gsl/string_span diff --git a/include/gsl/gsl b/include/gsl/gsl new file mode 100644 index 0000000..55862eb --- /dev/null +++ b/include/gsl/gsl @@ -0,0 +1,29 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_GSL_H +#define GSL_GSL_H + +#include // copy +#include // Ensures/Expects +#include // byte +#include // finally()/narrow()/narrow_cast()... +#include // multi_span, strided_span... +#include // owner, not_null +#include // span +#include // zstring, string_span, zstring_builder... + +#endif // GSL_GSL_H diff --git a/include/gsl/gsl_algorithm b/include/gsl/gsl_algorithm new file mode 100644 index 0000000..710792f --- /dev/null +++ b/include/gsl/gsl_algorithm @@ -0,0 +1,63 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_ALGORITHM_H +#define GSL_ALGORITHM_H + +#include // for Expects +#include // for dynamic_extent, span + +#include // for copy_n +#include // for ptrdiff_t +#include // for is_assignable + +#ifdef _MSC_VER +#pragma warning(push) + +// turn off some warnings that are noisy about our Expects statements +#pragma warning(disable : 4127) // conditional expression is constant +#pragma warning(disable : 4996) // unsafe use of std::copy_n + +// blanket turn off warnings from CppCoreCheck for now +// so people aren't annoyed by them when running the tool. +// more targeted suppressions will be added in a future update to the GSL +#pragma warning(disable : 26481 26482 26483 26485 26490 26491 26492 26493 26495) +#endif // _MSC_VER + +namespace gsl +{ + +template +void copy(span src, span dest) +{ + static_assert(std::is_assignable::value, + "Elements of source span can not be assigned to elements of destination span"); + static_assert(SrcExtent == dynamic_extent || DestExtent == dynamic_extent || + (SrcExtent <= DestExtent), + "Source range is longer than target range"); + + Expects(dest.size() >= src.size()); + std::copy_n(src.data(), src.size(), dest.data()); +} + +} // namespace gsl + +#ifdef _MSC_VER +#pragma warning(pop) +#endif // _MSC_VER + +#endif // GSL_ALGORITHM_H diff --git a/include/gsl/gsl_assert b/include/gsl/gsl_assert new file mode 100644 index 0000000..131fa8b --- /dev/null +++ b/include/gsl/gsl_assert @@ -0,0 +1,145 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_CONTRACTS_H +#define GSL_CONTRACTS_H + +#include +#include // for logic_error + +// +// Temporary until MSVC STL supports no-exceptions mode. +// Currently terminate is a no-op in this mode, so we add termination behavior back +// +#if defined(_MSC_VER) && defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS +#define GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND +#endif + +// +// There are three configuration options for this GSL implementation's behavior +// when pre/post conditions on the GSL types are violated: +// +// 1. GSL_TERMINATE_ON_CONTRACT_VIOLATION: std::terminate will be called (default) +// 2. GSL_THROW_ON_CONTRACT_VIOLATION: a gsl::fail_fast exception will be thrown +// 3. GSL_UNENFORCED_ON_CONTRACT_VIOLATION: nothing happens +// +#if !(defined(GSL_THROW_ON_CONTRACT_VIOLATION) || defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION) || \ + defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION)) +#define GSL_TERMINATE_ON_CONTRACT_VIOLATION +#endif + +#define GSL_STRINGIFY_DETAIL(x) #x +#define GSL_STRINGIFY(x) GSL_STRINGIFY_DETAIL(x) + +#if defined(__clang__) || defined(__GNUC__) +#define GSL_LIKELY(x) __builtin_expect(!!(x), 1) +#define GSL_UNLIKELY(x) __builtin_expect(!!(x), 0) +#else +#define GSL_LIKELY(x) (!!(x)) +#define GSL_UNLIKELY(x) (!!(x)) +#endif + +// +// GSL_ASSUME(cond) +// +// Tell the optimizer that the predicate cond must hold. It is unspecified +// whether or not cond is actually evaluated. +// +#ifdef _MSC_VER +#define GSL_ASSUME(cond) __assume(cond) +#elif defined(__GNUC__) +#define GSL_ASSUME(cond) ((cond) ? static_cast(0) : __builtin_unreachable()) +#else +#define GSL_ASSUME(cond) static_cast((cond) ? 0 : 0) +#endif + +// +// GSL.assert: assertions +// + +namespace gsl +{ +struct fail_fast : public std::logic_error +{ + explicit fail_fast(char const* const message) : std::logic_error(message) {} +}; + +namespace details +{ +#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND) + + typedef void (__cdecl *terminate_handler)(); + + inline gsl::details::terminate_handler& get_terminate_handler() noexcept + { + static terminate_handler handler = &abort; + return handler; + } + +#endif + + [[noreturn]] inline void terminate() noexcept + { +#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND) + (*gsl::details::get_terminate_handler())(); +#else + std::terminate(); +#endif + } + +#if defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION) + + template + [[noreturn]] void throw_exception(Exception&&) + { + gsl::details::terminate(); + } + +#else + + template + [[noreturn]] void throw_exception(Exception&& exception) + { + throw std::forward(exception); + } + +#endif + +} // namespace details +} // namespace gsl + +#if defined(GSL_THROW_ON_CONTRACT_VIOLATION) + +#define GSL_CONTRACT_CHECK(type, cond) \ + (GSL_LIKELY(cond) ? static_cast(0) \ + : gsl::details::throw_exception(gsl::fail_fast( \ + "GSL: " type " failure at " __FILE__ ": " GSL_STRINGIFY(__LINE__)))) + +#elif defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION) + +#define GSL_CONTRACT_CHECK(type, cond) \ + (GSL_LIKELY(cond) ? static_cast(0) : gsl::details::terminate()) + +#elif defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION) + +#define GSL_CONTRACT_CHECK(type, cond) GSL_ASSUME(cond) + +#endif + +#define Expects(cond) GSL_CONTRACT_CHECK("Precondition", cond) +#define Ensures(cond) GSL_CONTRACT_CHECK("Postcondition", cond) + +#endif // GSL_CONTRACTS_H diff --git a/include/gsl/gsl_byte b/include/gsl/gsl_byte new file mode 100644 index 0000000..e861173 --- /dev/null +++ b/include/gsl/gsl_byte @@ -0,0 +1,181 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_BYTE_H +#define GSL_BYTE_H + +#include + +#ifdef _MSC_VER + +#pragma warning(push) + +// don't warn about function style casts in byte related operators +#pragma warning(disable : 26493) + +#ifndef GSL_USE_STD_BYTE +// this tests if we are under MSVC and the standard lib has std::byte and it is enabled +#if defined(_HAS_STD_BYTE) && _HAS_STD_BYTE + +#define GSL_USE_STD_BYTE 1 + +#else // defined(_HAS_STD_BYTE) && _HAS_STD_BYTE + +#define GSL_USE_STD_BYTE 0 + +#endif // defined(_HAS_STD_BYTE) && _HAS_STD_BYTE +#endif // GSL_USE_STD_BYTE + +#else // _MSC_VER + +#ifndef GSL_USE_STD_BYTE +// this tests if we are under GCC or Clang with enough -std:c++1z power to get us std::byte +#if defined(__cplusplus) && (__cplusplus >= 201703L) + +#define GSL_USE_STD_BYTE 1 +#include + +#else // defined(__cplusplus) && (__cplusplus >= 201703L) + +#define GSL_USE_STD_BYTE 0 + +#endif //defined(__cplusplus) && (__cplusplus >= 201703L) +#endif // GSL_USE_STD_BYTE + +#endif // _MSC_VER + +// Use __may_alias__ attribute on gcc and clang +#if defined __clang__ || (__GNUC__ > 5) +#define byte_may_alias __attribute__((__may_alias__)) +#else // defined __clang__ || defined __GNUC__ +#define byte_may_alias +#endif // defined __clang__ || defined __GNUC__ + +namespace gsl +{ +#if GSL_USE_STD_BYTE + + +using std::byte; +using std::to_integer; + +#else // GSL_USE_STD_BYTE + +// This is a simple definition for now that allows +// use of byte within span<> to be standards-compliant +enum class byte_may_alias byte : unsigned char +{ +}; + +template ::value>> +constexpr byte& operator<<=(byte& b, IntegerType shift) noexcept +{ + return b = byte(static_cast(b) << shift); +} + +template ::value>> +constexpr byte operator<<(byte b, IntegerType shift) noexcept +{ + return byte(static_cast(b) << shift); +} + +template ::value>> +constexpr byte& operator>>=(byte& b, IntegerType shift) noexcept +{ + return b = byte(static_cast(b) >> shift); +} + +template ::value>> +constexpr byte operator>>(byte b, IntegerType shift) noexcept +{ + return byte(static_cast(b) >> shift); +} + +constexpr byte& operator|=(byte& l, byte r) noexcept +{ + return l = byte(static_cast(l) | static_cast(r)); +} + +constexpr byte operator|(byte l, byte r) noexcept +{ + return byte(static_cast(l) | static_cast(r)); +} + +constexpr byte& operator&=(byte& l, byte r) noexcept +{ + return l = byte(static_cast(l) & static_cast(r)); +} + +constexpr byte operator&(byte l, byte r) noexcept +{ + return byte(static_cast(l) & static_cast(r)); +} + +constexpr byte& operator^=(byte& l, byte r) noexcept +{ + return l = byte(static_cast(l) ^ static_cast(r)); +} + +constexpr byte operator^(byte l, byte r) noexcept +{ + return byte(static_cast(l) ^ static_cast(r)); +} + +constexpr byte operator~(byte b) noexcept { return byte(~static_cast(b)); } + +template ::value>> +constexpr IntegerType to_integer(byte b) noexcept +{ + return static_cast(b); +} + +#endif // GSL_USE_STD_BYTE + +template +constexpr byte to_byte_impl(T t) noexcept +{ + static_assert( + E, "gsl::to_byte(t) must be provided an unsigned char, otherwise data loss may occur. " + "If you are calling to_byte with an integer contant use: gsl::to_byte() version."); + return static_cast(t); +} +template <> +constexpr byte to_byte_impl(unsigned char t) noexcept +{ + return byte(t); +} + +template +constexpr byte to_byte(T t) noexcept +{ + return to_byte_impl::value, T>(t); +} + +template +constexpr byte to_byte() noexcept +{ + static_assert(I >= 0 && I <= 255, + "gsl::byte only has 8 bits of storage, values must be in range 0-255"); + return static_cast(I); +} + +} // namespace gsl + +#ifdef _MSC_VER +#pragma warning(pop) +#endif // _MSC_VER + +#endif // GSL_BYTE_H diff --git a/include/gsl/gsl_util b/include/gsl/gsl_util new file mode 100644 index 0000000..25f8502 --- /dev/null +++ b/include/gsl/gsl_util @@ -0,0 +1,158 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_UTIL_H +#define GSL_UTIL_H + +#include // for Expects + +#include +#include // for ptrdiff_t, size_t +#include // for exception +#include // for initializer_list +#include // for is_signed, integral_constant +#include // for forward + +#if defined(_MSC_VER) + +#pragma warning(push) +#pragma warning(disable : 4127) // conditional expression is constant + +#if _MSC_VER < 1910 +#pragma push_macro("constexpr") +#define constexpr /*constexpr*/ +#endif // _MSC_VER < 1910 +#endif // _MSC_VER + +namespace gsl +{ +// +// GSL.util: utilities +// + +// index type for all container indexes/subscripts/sizes +using index = std::ptrdiff_t; + +// final_action allows you to ensure something gets run at the end of a scope +template +class final_action +{ +public: + explicit final_action(F f) noexcept : f_(std::move(f)) {} + + final_action(final_action&& other) noexcept : f_(std::move(other.f_)), invoke_(other.invoke_) + { + other.invoke_ = false; + } + + final_action(const final_action&) = delete; + final_action& operator=(const final_action&) = delete; + final_action& operator=(final_action&&) = delete; + + ~final_action() noexcept + { + if (invoke_) f_(); + } + +private: + F f_; + bool invoke_ {true}; +}; + +// finally() - convenience function to generate a final_action +template + +final_action finally(const F& f) noexcept +{ + return final_action(f); +} + +template +final_action finally(F&& f) noexcept +{ + return final_action(std::forward(f)); +} + +// narrow_cast(): a searchable way to do narrowing casts of values +template +constexpr T narrow_cast(U&& u) noexcept +{ + return static_cast(std::forward(u)); +} + +struct narrowing_error : public std::exception +{ +}; + +namespace details +{ + template + struct is_same_signedness + : public std::integral_constant::value == std::is_signed::value> + { + }; +} + +// narrow() : a checked version of narrow_cast() that throws if the cast changed the value +template +T narrow(U u) +{ + T t = narrow_cast(u); + if (static_cast(t) != u) gsl::details::throw_exception(narrowing_error()); + if (!details::is_same_signedness::value && ((t < T{}) != (u < U{}))) + gsl::details::throw_exception(narrowing_error()); + return t; +} + +// +// at() - Bounds-checked way of accessing builtin arrays, std::array, std::vector +// +template +constexpr T& at(T (&arr)[N], const index i) +{ + Expects(i >= 0 && i < narrow_cast(N)); + return arr[static_cast(i)]; +} + +template +constexpr auto at(Cont& cont, const index i) -> decltype(cont[cont.size()]) +{ + Expects(i >= 0 && i < narrow_cast(cont.size())); + using size_type = decltype(cont.size()); + return cont[static_cast(i)]; +} + +template +constexpr T at(const std::initializer_list cont, const index i) +{ + Expects(i >= 0 && i < narrow_cast(cont.size())); + return *(cont.begin() + i); +} + +} // namespace gsl + +#if defined(_MSC_VER) +#if _MSC_VER < 1910 +#undef constexpr +#pragma pop_macro("constexpr") + +#endif // _MSC_VER < 1910 + +#pragma warning(pop) + +#endif // _MSC_VER + +#endif // GSL_UTIL_H diff --git a/include/gsl/multi_span b/include/gsl/multi_span new file mode 100644 index 0000000..9c0c27b --- /dev/null +++ b/include/gsl/multi_span @@ -0,0 +1,2242 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_MULTI_SPAN_H +#define GSL_MULTI_SPAN_H + +#include // for Expects +#include // for byte +#include // for narrow_cast + +#include // for transform, lexicographical_compare +#include // for array +#include +#include // for ptrdiff_t, size_t, nullptr_t +#include // for PTRDIFF_MAX +#include // for divides, multiplies, minus, negate, plus +#include // for initializer_list +#include // for iterator, random_access_iterator_tag +#include // for numeric_limits +#include +#include +#include +#include // for basic_string +#include // for enable_if_t, remove_cv_t, is_same, is_co... +#include + +#ifdef _MSC_VER + +// turn off some warnings that are noisy about our Expects statements +#pragma warning(push) +#pragma warning(disable : 4127) // conditional expression is constant +#pragma warning(disable : 4702) // unreachable code + +#if _MSC_VER < 1910 +#pragma push_macro("constexpr") +#define constexpr /*constexpr*/ + +#endif // _MSC_VER < 1910 +#endif // _MSC_VER + +// GCC 7 does not like the signed unsigned missmatch (size_t ptrdiff_t) +// While there is a conversion from signed to unsigned, it happens at +// compiletime, so the compiler wouldn't have to warn indiscriminently, but +// could check if the source value actually doesn't fit into the target type +// and only warn in those cases. +#if __GNUC__ > 6 +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wsign-conversion" +#endif + +#ifdef GSL_THROW_ON_CONTRACT_VIOLATION +#define GSL_NOEXCEPT /*noexcept*/ +#else +#define GSL_NOEXCEPT noexcept +#endif // GSL_THROW_ON_CONTRACT_VIOLATION + +namespace gsl +{ + +/* +** begin definitions of index and bounds +*/ +namespace details +{ + template + struct SizeTypeTraits + { + static const SizeType max_value = std::numeric_limits::max(); + }; + + template + class are_integral : public std::integral_constant + { + }; + + template + class are_integral + : public std::integral_constant::value && are_integral::value> + { + }; +} + +template +class multi_span_index final +{ + static_assert(Rank > 0, "Rank must be greater than 0!"); + + template + friend class multi_span_index; + +public: + static const std::size_t rank = Rank; + using value_type = std::ptrdiff_t; + using size_type = value_type; + using reference = std::add_lvalue_reference_t; + using const_reference = std::add_lvalue_reference_t>; + + constexpr multi_span_index() GSL_NOEXCEPT {} + + constexpr multi_span_index(const value_type (&values)[Rank]) GSL_NOEXCEPT + { + std::copy(values, values + Rank, elems); + } + + template ::value>> + constexpr multi_span_index(Ts... ds) GSL_NOEXCEPT : elems{narrow_cast(ds)...} + { + } + + constexpr multi_span_index(const multi_span_index& other) GSL_NOEXCEPT = default; + + constexpr multi_span_index& operator=(const multi_span_index& rhs) GSL_NOEXCEPT = default; + + // Preconditions: component_idx < rank + constexpr reference operator[](std::size_t component_idx) + { + Expects(component_idx < Rank); // Component index must be less than rank + return elems[component_idx]; + } + + // Preconditions: component_idx < rank + constexpr const_reference operator[](std::size_t component_idx) const GSL_NOEXCEPT + { + Expects(component_idx < Rank); // Component index must be less than rank + return elems[component_idx]; + } + + constexpr bool operator==(const multi_span_index& rhs) const GSL_NOEXCEPT + { + return std::equal(elems, elems + rank, rhs.elems); + } + + constexpr bool operator!=(const multi_span_index& rhs) const GSL_NOEXCEPT { return !(*this == rhs); } + + constexpr multi_span_index operator+() const GSL_NOEXCEPT { return *this; } + + constexpr multi_span_index operator-() const GSL_NOEXCEPT + { + multi_span_index ret = *this; + std::transform(ret, ret + rank, ret, std::negate{}); + return ret; + } + + constexpr multi_span_index operator+(const multi_span_index& rhs) const GSL_NOEXCEPT + { + multi_span_index ret = *this; + ret += rhs; + return ret; + } + + constexpr multi_span_index operator-(const multi_span_index& rhs) const GSL_NOEXCEPT + { + multi_span_index ret = *this; + ret -= rhs; + return ret; + } + + constexpr multi_span_index& operator+=(const multi_span_index& rhs) GSL_NOEXCEPT + { + std::transform(elems, elems + rank, rhs.elems, elems, std::plus{}); + return *this; + } + + constexpr multi_span_index& operator-=(const multi_span_index& rhs) GSL_NOEXCEPT + { + std::transform(elems, elems + rank, rhs.elems, elems, std::minus{}); + return *this; + } + + constexpr multi_span_index operator*(value_type v) const GSL_NOEXCEPT + { + multi_span_index ret = *this; + ret *= v; + return ret; + } + + constexpr multi_span_index operator/(value_type v) const GSL_NOEXCEPT + { + multi_span_index ret = *this; + ret /= v; + return ret; + } + + friend constexpr multi_span_index operator*(value_type v, const multi_span_index& rhs) GSL_NOEXCEPT + { + return rhs * v; + } + + constexpr multi_span_index& operator*=(value_type v) GSL_NOEXCEPT + { + std::transform(elems, elems + rank, elems, + [v](value_type x) { return std::multiplies{}(x, v); }); + return *this; + } + + constexpr multi_span_index& operator/=(value_type v) GSL_NOEXCEPT + { + std::transform(elems, elems + rank, elems, + [v](value_type x) { return std::divides{}(x, v); }); + return *this; + } + +private: + value_type elems[Rank] = {}; +}; + +#if !defined(_MSC_VER) || _MSC_VER >= 1910 + +struct static_bounds_dynamic_range_t +{ + template ::value>> + constexpr operator T() const GSL_NOEXCEPT + { + return narrow_cast(-1); + } +}; + +constexpr bool operator==(static_bounds_dynamic_range_t, static_bounds_dynamic_range_t) GSL_NOEXCEPT +{ + return true; +} + +constexpr bool operator!=(static_bounds_dynamic_range_t, static_bounds_dynamic_range_t) GSL_NOEXCEPT +{ + return false; +} + +template ::value>> +constexpr bool operator==(static_bounds_dynamic_range_t, T other) GSL_NOEXCEPT +{ + return narrow_cast(-1) == other; +} + +template ::value>> +constexpr bool operator==(T left, static_bounds_dynamic_range_t right) GSL_NOEXCEPT +{ + return right == left; +} + +template ::value>> +constexpr bool operator!=(static_bounds_dynamic_range_t, T other) GSL_NOEXCEPT +{ + return narrow_cast(-1) != other; +} + +template ::value>> +constexpr bool operator!=(T left, static_bounds_dynamic_range_t right) GSL_NOEXCEPT +{ + return right != left; +} + +constexpr static_bounds_dynamic_range_t dynamic_range{}; +#else +const std::ptrdiff_t dynamic_range = -1; +#endif + +struct generalized_mapping_tag +{ +}; +struct contiguous_mapping_tag : generalized_mapping_tag +{ +}; + +namespace details +{ + + template + struct LessThan + { + static const bool value = Left < Right; + }; + + template + struct BoundsRanges + { + using size_type = std::ptrdiff_t; + static const size_type Depth = 0; + static const size_type DynamicNum = 0; + static const size_type CurrentRange = 1; + static const size_type TotalSize = 1; + + // TODO : following signature is for work around VS bug + template + BoundsRanges(const OtherRange&, bool /* firstLevel */) + { + } + + BoundsRanges(const std::ptrdiff_t* const) {} + BoundsRanges() = default; + + template + void serialize(T&) const + { + } + + template + size_type linearize(const T&) const + { + return 0; + } + + template + size_type contains(const T&) const + { + return -1; + } + + size_type elementNum(std::size_t) const GSL_NOEXCEPT { return 0; } + + size_type totalSize() const GSL_NOEXCEPT { return TotalSize; } + + bool operator==(const BoundsRanges&) const GSL_NOEXCEPT { return true; } + }; + + template + struct BoundsRanges : BoundsRanges + { + using Base = BoundsRanges; + using size_type = std::ptrdiff_t; + static const std::size_t Depth = Base::Depth + 1; + static const std::size_t DynamicNum = Base::DynamicNum + 1; + static const size_type CurrentRange = dynamic_range; + static const size_type TotalSize = dynamic_range; + + private: + size_type m_bound; + + public: + BoundsRanges(const std::ptrdiff_t* const arr) + : Base(arr + 1), m_bound(*arr * this->Base::totalSize()) + { + Expects(0 <= *arr); + } + + BoundsRanges() : m_bound(0) {} + + template + BoundsRanges(const BoundsRanges& other, + bool /* firstLevel */ = true) + : Base(static_cast&>(other), false) + , m_bound(other.totalSize()) + { + } + + template + void serialize(T& arr) const + { + arr[Dim] = elementNum(); + this->Base::template serialize(arr); + } + + template + size_type linearize(const T& arr) const + { + const size_type index = this->Base::totalSize() * arr[Dim]; + Expects(index < m_bound); + return index + this->Base::template linearize(arr); + } + + template + size_type contains(const T& arr) const + { + const ptrdiff_t last = this->Base::template contains(arr); + if (last == -1) return -1; + const ptrdiff_t cur = this->Base::totalSize() * arr[Dim]; + return cur < m_bound ? cur + last : -1; + } + + size_type totalSize() const GSL_NOEXCEPT { return m_bound; } + + size_type elementNum() const GSL_NOEXCEPT { return totalSize() / this->Base::totalSize(); } + + size_type elementNum(std::size_t dim) const GSL_NOEXCEPT + { + if (dim > 0) + return this->Base::elementNum(dim - 1); + else + return elementNum(); + } + + bool operator==(const BoundsRanges& rhs) const GSL_NOEXCEPT + { + return m_bound == rhs.m_bound && + static_cast(*this) == static_cast(rhs); + } + }; + + template + struct BoundsRanges : BoundsRanges + { + using Base = BoundsRanges; + using size_type = std::ptrdiff_t; + static const std::size_t Depth = Base::Depth + 1; + static const std::size_t DynamicNum = Base::DynamicNum; + static const size_type CurrentRange = CurRange; + static const size_type TotalSize = + Base::TotalSize == dynamic_range ? dynamic_range : CurrentRange * Base::TotalSize; + + BoundsRanges(const std::ptrdiff_t* const arr) : Base(arr) {} + BoundsRanges() = default; + + template + BoundsRanges(const BoundsRanges& other, + bool firstLevel = true) + : Base(static_cast&>(other), false) + { + (void) firstLevel; + } + + template + void serialize(T& arr) const + { + arr[Dim] = elementNum(); + this->Base::template serialize(arr); + } + + template + size_type linearize(const T& arr) const + { + Expects(arr[Dim] >= 0 && arr[Dim] < CurrentRange); // Index is out of range + return this->Base::totalSize() * arr[Dim] + + this->Base::template linearize(arr); + } + + template + size_type contains(const T& arr) const + { + if (arr[Dim] >= CurrentRange) return -1; + const size_type last = this->Base::template contains(arr); + if (last == -1) return -1; + return this->Base::totalSize() * arr[Dim] + last; + } + + size_type totalSize() const GSL_NOEXCEPT { return CurrentRange * this->Base::totalSize(); } + + size_type elementNum() const GSL_NOEXCEPT { return CurrentRange; } + + size_type elementNum(std::size_t dim) const GSL_NOEXCEPT + { + if (dim > 0) + return this->Base::elementNum(dim - 1); + else + return elementNum(); + } + + bool operator==(const BoundsRanges& rhs) const GSL_NOEXCEPT + { + return static_cast(*this) == static_cast(rhs); + } + }; + + template + struct BoundsRangeConvertible + : public std::integral_constant= TargetType::TotalSize || + TargetType::TotalSize == dynamic_range || + SourceType::TotalSize == dynamic_range || + TargetType::TotalSize == 0)> + { + }; + + template + struct TypeListIndexer + { + const TypeChain& obj_; + TypeListIndexer(const TypeChain& obj) : obj_(obj) {} + + template + const TypeChain& getObj(std::true_type) + { + return obj_; + } + + template + auto getObj(std::false_type) + -> decltype(TypeListIndexer(static_cast(obj_)).template get()) + { + return TypeListIndexer(static_cast(obj_)).template get(); + } + + template + auto get() -> decltype(getObj(std::integral_constant())) + { + return getObj(std::integral_constant()); + } + }; + + template + TypeListIndexer createTypeListIndexer(const TypeChain& obj) + { + return TypeListIndexer(obj); + } + + template 1), + typename Ret = std::enable_if_t>> + constexpr Ret shift_left(const multi_span_index& other) GSL_NOEXCEPT + { + Ret ret{}; + for (std::size_t i = 0; i < Rank - 1; ++i) { + ret[i] = other[i + 1]; + } + return ret; + } +} + +template +class bounds_iterator; + +template +class static_bounds +{ +public: + static_bounds(const details::BoundsRanges&) {} +}; + +template +class static_bounds +{ + using MyRanges = details::BoundsRanges; + + MyRanges m_ranges; + constexpr static_bounds(const MyRanges& range) : m_ranges(range) {} + + template + friend class static_bounds; + +public: + static const std::size_t rank = MyRanges::Depth; + static const std::size_t dynamic_rank = MyRanges::DynamicNum; + static const std::ptrdiff_t static_size = MyRanges::TotalSize; + + using size_type = std::ptrdiff_t; + using index_type = multi_span_index; + using const_index_type = std::add_const_t; + using iterator = bounds_iterator; + using const_iterator = bounds_iterator; + using difference_type = std::ptrdiff_t; + using sliced_type = static_bounds; + using mapping_type = contiguous_mapping_tag; + + constexpr static_bounds(const static_bounds&) = default; + + template + struct BoundsRangeConvertible2; + + template > + static auto helpBoundsRangeConvertible(SourceType, TargetType, std::true_type) -> Ret; + + template + static auto helpBoundsRangeConvertible(SourceType, TargetType, ...) -> std::false_type; + + template + struct BoundsRangeConvertible2 + : decltype(helpBoundsRangeConvertible( + SourceType(), TargetType(), + std::integral_constant())) + { + }; + + template + struct BoundsRangeConvertible2 : std::true_type + { + }; + + template + struct BoundsRangeConvertible + : decltype(helpBoundsRangeConvertible( + SourceType(), TargetType(), + std::integral_constant::value || + TargetType::CurrentRange == dynamic_range || + SourceType::CurrentRange == dynamic_range)>())) + { + }; + + template + struct BoundsRangeConvertible : std::true_type + { + }; + + template , + details::BoundsRanges>::value>> + constexpr static_bounds(const static_bounds& other) : m_ranges(other.m_ranges) + { + Expects((MyRanges::DynamicNum == 0 && details::BoundsRanges::DynamicNum == 0) || + MyRanges::DynamicNum > 0 || other.m_ranges.totalSize() >= m_ranges.totalSize()); + } + + constexpr static_bounds(std::initializer_list il) + : m_ranges(il.begin()) + { + // Size of the initializer list must match the rank of the array + Expects((MyRanges::DynamicNum == 0 && il.size() == 1 && *il.begin() == static_size) || + MyRanges::DynamicNum == il.size()); + // Size of the range must be less than the max element of the size type + Expects(m_ranges.totalSize() <= PTRDIFF_MAX); + } + + constexpr static_bounds() = default; + + constexpr sliced_type slice() const GSL_NOEXCEPT + { + return sliced_type{static_cast&>(m_ranges)}; + } + + constexpr size_type stride() const GSL_NOEXCEPT { return rank > 1 ? slice().size() : 1; } + + constexpr size_type size() const GSL_NOEXCEPT { return m_ranges.totalSize(); } + + constexpr size_type total_size() const GSL_NOEXCEPT { return m_ranges.totalSize(); } + + constexpr size_type linearize(const index_type& idx) const { return m_ranges.linearize(idx); } + + constexpr bool contains(const index_type& idx) const GSL_NOEXCEPT + { + return m_ranges.contains(idx) != -1; + } + + constexpr size_type operator[](std::size_t idx) const GSL_NOEXCEPT + { + return m_ranges.elementNum(idx); + } + + template + constexpr size_type extent() const GSL_NOEXCEPT + { + static_assert(Dim < rank, + "dimension should be less than rank (dimension count starts from 0)"); + return details::createTypeListIndexer(m_ranges).template get().elementNum(); + } + + template + constexpr size_type extent(IntType dim) const GSL_NOEXCEPT + { + static_assert(std::is_integral::value, + "Dimension parameter must be supplied as an integral type."); + auto real_dim = narrow_cast(dim); + Expects(real_dim < rank); + + return m_ranges.elementNum(real_dim); + } + + constexpr index_type index_bounds() const GSL_NOEXCEPT + { + size_type extents[rank] = {}; + m_ranges.serialize(extents); + return {extents}; + } + + template + constexpr bool operator==(const static_bounds& rhs) const GSL_NOEXCEPT + { + return this->size() == rhs.size(); + } + + template + constexpr bool operator!=(const static_bounds& rhs) const GSL_NOEXCEPT + { + return !(*this == rhs); + } + + constexpr const_iterator begin() const GSL_NOEXCEPT + { + return const_iterator(*this, index_type{}); + } + + constexpr const_iterator end() const GSL_NOEXCEPT + { + return const_iterator(*this, this->index_bounds()); + } +}; + +template +class strided_bounds +{ + template + friend class strided_bounds; + +public: + static const std::size_t rank = Rank; + using value_type = std::ptrdiff_t; + using reference = std::add_lvalue_reference_t; + using const_reference = std::add_const_t; + using size_type = value_type; + using difference_type = value_type; + using index_type = multi_span_index; + using const_index_type = std::add_const_t; + using iterator = bounds_iterator; + using const_iterator = bounds_iterator; + static const value_type dynamic_rank = rank; + static const value_type static_size = dynamic_range; + using sliced_type = std::conditional_t, void>; + using mapping_type = generalized_mapping_tag; + + constexpr strided_bounds(const strided_bounds&) GSL_NOEXCEPT = default; + + constexpr strided_bounds& operator=(const strided_bounds&) GSL_NOEXCEPT = default; + + constexpr strided_bounds(const value_type (&values)[rank], index_type strides) + : m_extents(values), m_strides(std::move(strides)) + { + } + + constexpr strided_bounds(const index_type& extents, const index_type& strides) GSL_NOEXCEPT + : m_extents(extents), + m_strides(strides) + { + } + + constexpr index_type strides() const GSL_NOEXCEPT { return m_strides; } + + constexpr size_type total_size() const GSL_NOEXCEPT + { + size_type ret = 0; + for (std::size_t i = 0; i < rank; ++i) { + ret += (m_extents[i] - 1) * m_strides[i]; + } + return ret + 1; + } + + constexpr size_type size() const GSL_NOEXCEPT + { + size_type ret = 1; + for (std::size_t i = 0; i < rank; ++i) { + ret *= m_extents[i]; + } + return ret; + } + + constexpr bool contains(const index_type& idx) const GSL_NOEXCEPT + { + for (std::size_t i = 0; i < rank; ++i) { + if (idx[i] < 0 || idx[i] >= m_extents[i]) return false; + } + return true; + } + + constexpr size_type linearize(const index_type& idx) const GSL_NOEXCEPT + { + size_type ret = 0; + for (std::size_t i = 0; i < rank; i++) { + Expects(idx[i] < m_extents[i]); // index is out of bounds of the array + ret += idx[i] * m_strides[i]; + } + return ret; + } + + constexpr size_type stride() const GSL_NOEXCEPT { return m_strides[0]; } + + template 1), typename Ret = std::enable_if_t> + constexpr sliced_type slice() const + { + return {details::shift_left(m_extents), details::shift_left(m_strides)}; + } + + template + constexpr size_type extent() const GSL_NOEXCEPT + { + static_assert(Dim < Rank, + "dimension should be less than rank (dimension count starts from 0)"); + return m_extents[Dim]; + } + + constexpr index_type index_bounds() const GSL_NOEXCEPT { return m_extents; } + constexpr const_iterator begin() const GSL_NOEXCEPT + { + return const_iterator{*this, index_type{}}; + } + + constexpr const_iterator end() const GSL_NOEXCEPT + { + return const_iterator{*this, index_bounds()}; + } + +private: + index_type m_extents; + index_type m_strides; +}; + +template +struct is_bounds : std::integral_constant +{ +}; +template +struct is_bounds> : std::integral_constant +{ +}; +template +struct is_bounds> : std::integral_constant +{ +}; + +template +class bounds_iterator +{ +public: + static const std::size_t rank = IndexType::rank; + using iterator_category = std::random_access_iterator_tag; + using value_type = IndexType; + using difference_type = std::ptrdiff_t; + using pointer = value_type*; + using reference = value_type&; + using index_type = value_type; + using index_size_type = typename IndexType::value_type; + template + explicit bounds_iterator(const Bounds& bnd, value_type curr) GSL_NOEXCEPT + : boundary_(bnd.index_bounds()), + curr_(std::move(curr)) + { + static_assert(is_bounds::value, "Bounds type must be provided"); + } + + constexpr reference operator*() const GSL_NOEXCEPT { return curr_; } + + constexpr pointer operator->() const GSL_NOEXCEPT { return &curr_; } + + constexpr bounds_iterator& operator++() GSL_NOEXCEPT + { + for (std::size_t i = rank; i-- > 0;) { + if (curr_[i] < boundary_[i] - 1) { + curr_[i]++; + return *this; + } + curr_[i] = 0; + } + // If we're here we've wrapped over - set to past-the-end. + curr_ = boundary_; + return *this; + } + + constexpr bounds_iterator operator++(int) GSL_NOEXCEPT + { + auto ret = *this; + ++(*this); + return ret; + } + + constexpr bounds_iterator& operator--() GSL_NOEXCEPT + { + if (!less(curr_, boundary_)) { + // if at the past-the-end, set to last element + for (std::size_t i = 0; i < rank; ++i) { + curr_[i] = boundary_[i] - 1; + } + return *this; + } + for (std::size_t i = rank; i-- > 0;) { + if (curr_[i] >= 1) { + curr_[i]--; + return *this; + } + curr_[i] = boundary_[i] - 1; + } + // If we're here the preconditions were violated + // "pre: there exists s such that r == ++s" + Expects(false); + return *this; + } + + constexpr bounds_iterator operator--(int) GSL_NOEXCEPT + { + auto ret = *this; + --(*this); + return ret; + } + + constexpr bounds_iterator operator+(difference_type n) const GSL_NOEXCEPT + { + bounds_iterator ret{*this}; + return ret += n; + } + + constexpr bounds_iterator& operator+=(difference_type n) GSL_NOEXCEPT + { + auto linear_idx = linearize(curr_) + n; + std::remove_const_t stride = 0; + stride[rank - 1] = 1; + for (std::size_t i = rank - 1; i-- > 0;) { + stride[i] = stride[i + 1] * boundary_[i + 1]; + } + for (std::size_t i = 0; i < rank; ++i) { + curr_[i] = linear_idx / stride[i]; + linear_idx = linear_idx % stride[i]; + } + // index is out of bounds of the array + Expects(!less(curr_, index_type{}) && !less(boundary_, curr_)); + return *this; + } + + constexpr bounds_iterator operator-(difference_type n) const GSL_NOEXCEPT + { + bounds_iterator ret{*this}; + return ret -= n; + } + + constexpr bounds_iterator& operator-=(difference_type n) GSL_NOEXCEPT { return *this += -n; } + + constexpr difference_type operator-(const bounds_iterator& rhs) const GSL_NOEXCEPT + { + return linearize(curr_) - linearize(rhs.curr_); + } + + constexpr value_type operator[](difference_type n) const GSL_NOEXCEPT { return *(*this + n); } + + constexpr bool operator==(const bounds_iterator& rhs) const GSL_NOEXCEPT + { + return curr_ == rhs.curr_; + } + + constexpr bool operator!=(const bounds_iterator& rhs) const GSL_NOEXCEPT + { + return !(*this == rhs); + } + + constexpr bool operator<(const bounds_iterator& rhs) const GSL_NOEXCEPT + { + return less(curr_, rhs.curr_); + } + + constexpr bool operator<=(const bounds_iterator& rhs) const GSL_NOEXCEPT + { + return !(rhs < *this); + } + + constexpr bool operator>(const bounds_iterator& rhs) const GSL_NOEXCEPT { return rhs < *this; } + + constexpr bool operator>=(const bounds_iterator& rhs) const GSL_NOEXCEPT + { + return !(rhs > *this); + } + + void swap(bounds_iterator& rhs) GSL_NOEXCEPT + { + std::swap(boundary_, rhs.boundary_); + std::swap(curr_, rhs.curr_); + } + +private: + constexpr bool less(index_type& one, index_type& other) const GSL_NOEXCEPT + { + for (std::size_t i = 0; i < rank; ++i) { + if (one[i] < other[i]) return true; + } + return false; + } + + constexpr index_size_type linearize(const value_type& idx) const GSL_NOEXCEPT + { + // TODO: Smarter impl. + // Check if past-the-end + index_size_type multiplier = 1; + index_size_type res = 0; + if (!less(idx, boundary_)) { + res = 1; + for (std::size_t i = rank; i-- > 0;) { + res += (idx[i] - 1) * multiplier; + multiplier *= boundary_[i]; + } + } + else + { + for (std::size_t i = rank; i-- > 0;) { + res += idx[i] * multiplier; + multiplier *= boundary_[i]; + } + } + return res; + } + + value_type boundary_; + std::remove_const_t curr_; +}; + +template +bounds_iterator operator+(typename bounds_iterator::difference_type n, + const bounds_iterator& rhs) GSL_NOEXCEPT +{ + return rhs + n; +} + +namespace details +{ + template + constexpr std::enable_if_t< + std::is_same::value, + typename Bounds::index_type> + make_stride(const Bounds& bnd) GSL_NOEXCEPT + { + return bnd.strides(); + } + + // Make a stride vector from bounds, assuming contiguous memory. + template + constexpr std::enable_if_t< + std::is_same::value, + typename Bounds::index_type> + make_stride(const Bounds& bnd) GSL_NOEXCEPT + { + auto extents = bnd.index_bounds(); + typename Bounds::size_type stride[Bounds::rank] = {}; + + stride[Bounds::rank - 1] = 1; + for (std::size_t i = 1; i < Bounds::rank; ++i) { + stride[Bounds::rank - i - 1] = stride[Bounds::rank - i] * extents[Bounds::rank - i]; + } + return {stride}; + } + + template + void verifyBoundsReshape(const BoundsSrc& src, const BoundsDest& dest) + { + static_assert(is_bounds::value && is_bounds::value, + "The src type and dest type must be bounds"); + static_assert(std::is_same::value, + "The source type must be a contiguous bounds"); + static_assert(BoundsDest::static_size == dynamic_range || + BoundsSrc::static_size == dynamic_range || + BoundsDest::static_size == BoundsSrc::static_size, + "The source bounds must have same size as dest bounds"); + Expects(src.size() == dest.size()); + } + +} // namespace details + +template +class contiguous_span_iterator; +template +class general_span_iterator; + +template +struct dim_t +{ + static const std::ptrdiff_t value = DimSize; +}; +template <> +struct dim_t +{ + static const std::ptrdiff_t value = dynamic_range; + const std::ptrdiff_t dvalue; + constexpr dim_t(std::ptrdiff_t size) GSL_NOEXCEPT : dvalue(size) {} +}; + +template = 0)>> +constexpr dim_t dim() GSL_NOEXCEPT +{ + return dim_t(); +} + +template > +constexpr dim_t dim(std::ptrdiff_t n) GSL_NOEXCEPT +{ + return dim_t<>(n); +} + +template +class multi_span; +template +class strided_span; + +namespace details +{ + template + struct SpanTypeTraits + { + using value_type = T; + using size_type = std::size_t; + }; + + template + struct SpanTypeTraits::type> + { + using value_type = typename Traits::span_traits::value_type; + using size_type = typename Traits::span_traits::size_type; + }; + + template + struct SpanArrayTraits + { + using type = multi_span; + using value_type = T; + using bounds_type = static_bounds; + using pointer = T*; + using reference = T&; + }; + template + struct SpanArrayTraits : SpanArrayTraits + { + }; + + template + BoundsType newBoundsHelperImpl(std::ptrdiff_t totalSize, std::true_type) // dynamic size + { + Expects(totalSize >= 0 && totalSize <= PTRDIFF_MAX); + return BoundsType{totalSize}; + } + template + BoundsType newBoundsHelperImpl(std::ptrdiff_t totalSize, std::false_type) // static size + { + Expects(BoundsType::static_size <= totalSize); + return {}; + } + template + BoundsType newBoundsHelper(std::ptrdiff_t totalSize) + { + static_assert(BoundsType::dynamic_rank <= 1, "dynamic rank must less or equal to 1"); + return newBoundsHelperImpl( + totalSize, std::integral_constant()); + } + + struct Sep + { + }; + + template + T static_as_multi_span_helper(Sep, Args... args) + { + return T{narrow_cast(args)...}; + } + template + std::enable_if_t< + !std::is_same>::value && !std::is_same::value, T> + static_as_multi_span_helper(Arg, Args... args) + { + return static_as_multi_span_helper(args...); + } + template + T static_as_multi_span_helper(dim_t val, Args... args) + { + return static_as_multi_span_helper(args..., val.dvalue); + } + + template + struct static_as_multi_span_static_bounds_helper + { + using type = static_bounds<(Dimensions::value)...>; + }; + + template + struct is_multi_span_oracle : std::false_type + { + }; + + template + struct is_multi_span_oracle> + : std::true_type + { + }; + + template + struct is_multi_span_oracle> : std::true_type + { + }; + + template + struct is_multi_span : is_multi_span_oracle> + { + }; +} + +template +class multi_span +{ + // TODO do we still need this? + template + friend class multi_span; + +public: + using bounds_type = static_bounds; + static const std::size_t Rank = bounds_type::rank; + using size_type = typename bounds_type::size_type; + using index_type = typename bounds_type::index_type; + using value_type = ValueType; + using const_value_type = std::add_const_t; + using pointer = std::add_pointer_t; + using reference = std::add_lvalue_reference_t; + using iterator = contiguous_span_iterator; + using const_span = multi_span; + using const_iterator = contiguous_span_iterator; + using reverse_iterator = std::reverse_iterator; + using const_reverse_iterator = std::reverse_iterator; + using sliced_type = + std::conditional_t>; + +private: + pointer data_; + bounds_type bounds_; + + friend iterator; + friend const_iterator; + +public: + // default constructor - same as constructing from nullptr_t + constexpr multi_span() GSL_NOEXCEPT : multi_span(nullptr, bounds_type{}) + { + static_assert(bounds_type::dynamic_rank != 0 || + (bounds_type::dynamic_rank == 0 && bounds_type::static_size == 0), + "Default construction of multi_span only possible " + "for dynamic or fixed, zero-length spans."); + } + + // construct from nullptr - get an empty multi_span + constexpr multi_span(std::nullptr_t) GSL_NOEXCEPT : multi_span(nullptr, bounds_type{}) + { + static_assert(bounds_type::dynamic_rank != 0 || + (bounds_type::dynamic_rank == 0 && bounds_type::static_size == 0), + "nullptr_t construction of multi_span only possible " + "for dynamic or fixed, zero-length spans."); + } + + // construct from nullptr with size of 0 (helps with template function calls) + template ::value>> + constexpr multi_span(std::nullptr_t, IntType size) GSL_NOEXCEPT + : multi_span(nullptr, bounds_type{}) + { + static_assert(bounds_type::dynamic_rank != 0 || + (bounds_type::dynamic_rank == 0 && bounds_type::static_size == 0), + "nullptr_t construction of multi_span only possible " + "for dynamic or fixed, zero-length spans."); + Expects(size == 0); + } + + // construct from a single element + constexpr multi_span(reference data) GSL_NOEXCEPT : multi_span(&data, bounds_type{1}) + { + static_assert(bounds_type::dynamic_rank > 0 || bounds_type::static_size == 0 || + bounds_type::static_size == 1, + "Construction from a single element only possible " + "for dynamic or fixed spans of length 0 or 1."); + } + + // prevent constructing from temporaries for single-elements + constexpr multi_span(value_type&&) = delete; + + // construct from pointer + length + constexpr multi_span(pointer ptr, size_type size) GSL_NOEXCEPT + : multi_span(ptr, bounds_type{size}) + { + } + + // construct from pointer + length - multidimensional + constexpr multi_span(pointer data, bounds_type bounds) GSL_NOEXCEPT : data_(data), + bounds_(std::move(bounds)) + { + Expects((bounds_.size() > 0 && data != nullptr) || bounds_.size() == 0); + } + + // construct from begin,end pointer pair + template ::value && + details::LessThan::value>> + constexpr multi_span(pointer begin, Ptr end) + : multi_span(begin, + details::newBoundsHelper(static_cast(end) - begin)) + { + Expects(begin != nullptr && end != nullptr && begin <= static_cast(end)); + } + + // construct from n-dimensions static array + template > + constexpr multi_span(T (&arr)[N]) + : multi_span(reinterpret_cast(arr), bounds_type{typename Helper::bounds_type{}}) + { + static_assert(std::is_convertible::value, + "Cannot convert from source type to target multi_span type."); + static_assert(std::is_convertible::value, + "Cannot construct a multi_span from an array with fewer elements."); + } + + // construct from n-dimensions dynamic array (e.g. new int[m][4]) + // (precedence will be lower than the 1-dimension pointer) + template > + constexpr multi_span(T* const& data, size_type size) + : multi_span(reinterpret_cast(data), typename Helper::bounds_type{size}) + { + static_assert(std::is_convertible::value, + "Cannot convert from source type to target multi_span type."); + } + + // construct from std::array + template + constexpr multi_span(std::array& arr) + : multi_span(arr.data(), bounds_type{static_bounds{}}) + { + static_assert( + std::is_convertible(*)[]>::value, + "Cannot convert from source type to target multi_span type."); + static_assert(std::is_convertible, bounds_type>::value, + "You cannot construct a multi_span from a std::array of smaller size."); + } + + // construct from const std::array + template + constexpr multi_span(const std::array& arr) + : multi_span(arr.data(), bounds_type{static_bounds{}}) + { + static_assert(std::is_convertible(*)[]>::value, + "Cannot convert from source type to target multi_span type."); + static_assert(std::is_convertible, bounds_type>::value, + "You cannot construct a multi_span from a std::array of smaller size."); + } + + // prevent constructing from temporary std::array + template + constexpr multi_span(std::array&& arr) = delete; + + // construct from containers + // future: could use contiguous_iterator_traits to identify only contiguous containers + // type-requirements: container must have .size(), operator[] which are value_type compatible + template ::value && + std::is_convertible::value && + std::is_same().size(), + *std::declval().data())>, + DataType>::value>> + constexpr multi_span(Cont& cont) + : multi_span(static_cast(cont.data()), + details::newBoundsHelper(narrow_cast(cont.size()))) + { + } + + // prevent constructing from temporary containers + template ::value && + std::is_convertible::value && + std::is_same().size(), + *std::declval().data())>, + DataType>::value>> + explicit constexpr multi_span(Cont&& cont) = delete; + + // construct from a convertible multi_span + template , + typename = std::enable_if_t::value && + std::is_convertible::value>> + constexpr multi_span(multi_span other) GSL_NOEXCEPT + : data_(other.data_), + bounds_(other.bounds_) + { + } + + // trivial copy and move + constexpr multi_span(const multi_span&) = default; + constexpr multi_span(multi_span&&) = default; + + // trivial assignment + constexpr multi_span& operator=(const multi_span&) = default; + constexpr multi_span& operator=(multi_span&&) = default; + + // first() - extract the first Count elements into a new multi_span + template + constexpr multi_span first() const GSL_NOEXCEPT + { + static_assert(Count >= 0, "Count must be >= 0."); + static_assert(bounds_type::static_size == dynamic_range || + Count <= bounds_type::static_size, + "Count is out of bounds."); + + Expects(bounds_type::static_size != dynamic_range || Count <= this->size()); + return {this->data(), Count}; + } + + // first() - extract the first count elements into a new multi_span + constexpr multi_span first(size_type count) const GSL_NOEXCEPT + { + Expects(count >= 0 && count <= this->size()); + return {this->data(), count}; + } + + // last() - extract the last Count elements into a new multi_span + template + constexpr multi_span last() const GSL_NOEXCEPT + { + static_assert(Count >= 0, "Count must be >= 0."); + static_assert(bounds_type::static_size == dynamic_range || + Count <= bounds_type::static_size, + "Count is out of bounds."); + + Expects(bounds_type::static_size != dynamic_range || Count <= this->size()); + return {this->data() + this->size() - Count, Count}; + } + + // last() - extract the last count elements into a new multi_span + constexpr multi_span last(size_type count) const GSL_NOEXCEPT + { + Expects(count >= 0 && count <= this->size()); + return {this->data() + this->size() - count, count}; + } + + // subspan() - create a subview of Count elements starting at Offset + template + constexpr multi_span subspan() const GSL_NOEXCEPT + { + static_assert(Count >= 0, "Count must be >= 0."); + static_assert(Offset >= 0, "Offset must be >= 0."); + static_assert(bounds_type::static_size == dynamic_range || + ((Offset <= bounds_type::static_size) && + Count <= bounds_type::static_size - Offset), + "You must describe a sub-range within bounds of the multi_span."); + + Expects(bounds_type::static_size != dynamic_range || + (Offset <= this->size() && Count <= this->size() - Offset)); + return {this->data() + Offset, Count}; + } + + // subspan() - create a subview of count elements starting at offset + // supplying dynamic_range for count will consume all available elements from offset + constexpr multi_span + subspan(size_type offset, size_type count = dynamic_range) const GSL_NOEXCEPT + { + Expects((offset >= 0 && offset <= this->size()) && + (count == dynamic_range || (count <= this->size() - offset))); + return {this->data() + offset, count == dynamic_range ? this->length() - offset : count}; + } + + // section - creates a non-contiguous, strided multi_span from a contiguous one + constexpr strided_span section(index_type origin, + index_type extents) const GSL_NOEXCEPT + { + size_type size = this->bounds().total_size() - this->bounds().linearize(origin); + return {&this->operator[](origin), size, + strided_bounds{extents, details::make_stride(bounds())}}; + } + + // length of the multi_span in elements + constexpr size_type size() const GSL_NOEXCEPT { return bounds_.size(); } + + // length of the multi_span in elements + constexpr size_type length() const GSL_NOEXCEPT { return this->size(); } + + // length of the multi_span in bytes + constexpr size_type size_bytes() const GSL_NOEXCEPT + { + return narrow_cast(sizeof(value_type)) * this->size(); + } + + // length of the multi_span in bytes + constexpr size_type length_bytes() const GSL_NOEXCEPT { return this->size_bytes(); } + + constexpr bool empty() const GSL_NOEXCEPT { return this->size() == 0; } + + static constexpr std::size_t rank() { return Rank; } + + template + constexpr size_type extent() const GSL_NOEXCEPT + { + static_assert(Dim < Rank, + "Dimension should be less than rank (dimension count starts from 0)."); + return bounds_.template extent(); + } + + template + constexpr size_type extent(IntType dim) const GSL_NOEXCEPT + { + return bounds_.extent(dim); + } + + constexpr bounds_type bounds() const GSL_NOEXCEPT { return bounds_; } + + constexpr pointer data() const GSL_NOEXCEPT { return data_; } + + template + constexpr reference operator()(FirstIndex idx) + { + return this->operator[](narrow_cast(idx)); + } + + template + constexpr reference operator()(FirstIndex firstIndex, OtherIndices... indices) + { + index_type idx = {narrow_cast(firstIndex), + narrow_cast(indices)...}; + return this->operator[](idx); + } + + constexpr reference operator[](const index_type& idx) const GSL_NOEXCEPT + { + return data_[bounds_.linearize(idx)]; + } + + template 1), typename Ret = std::enable_if_t> + constexpr Ret operator[](size_type idx) const GSL_NOEXCEPT + { + Expects(idx >= 0 && idx < bounds_.size()); // index is out of bounds of the array + const size_type ridx = idx * bounds_.stride(); + + // index is out of bounds of the underlying data + Expects(ridx < bounds_.total_size()); + return Ret{data_ + ridx, bounds_.slice()}; + } + + constexpr iterator begin() const GSL_NOEXCEPT { return iterator{this, true}; } + + constexpr iterator end() const GSL_NOEXCEPT { return iterator{this, false}; } + + constexpr const_iterator cbegin() const GSL_NOEXCEPT + { + return const_iterator{reinterpret_cast(this), true}; + } + + constexpr const_iterator cend() const GSL_NOEXCEPT + { + return const_iterator{reinterpret_cast(this), false}; + } + + constexpr reverse_iterator rbegin() const GSL_NOEXCEPT { return reverse_iterator{end()}; } + + constexpr reverse_iterator rend() const GSL_NOEXCEPT { return reverse_iterator{begin()}; } + + constexpr const_reverse_iterator crbegin() const GSL_NOEXCEPT + { + return const_reverse_iterator{cend()}; + } + + constexpr const_reverse_iterator crend() const GSL_NOEXCEPT + { + return const_reverse_iterator{cbegin()}; + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator==(const multi_span& other) const GSL_NOEXCEPT + { + return bounds_.size() == other.bounds_.size() && + (data_ == other.data_ || std::equal(this->begin(), this->end(), other.begin())); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator!=(const multi_span& other) const GSL_NOEXCEPT + { + return !(*this == other); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator<(const multi_span& other) const GSL_NOEXCEPT + { + return std::lexicographical_compare(this->begin(), this->end(), other.begin(), other.end()); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator<=(const multi_span& other) const GSL_NOEXCEPT + { + return !(other < *this); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator>(const multi_span& other) const GSL_NOEXCEPT + { + return (other < *this); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator>=(const multi_span& other) const GSL_NOEXCEPT + { + return !(*this < other); + } +}; + +// +// Free functions for manipulating spans +// + +// reshape a multi_span into a different dimensionality +// DimCount and Enabled here are workarounds for a bug in MSVC 2015 +template 0), typename = std::enable_if_t> +constexpr auto as_multi_span(SpanType s, Dimensions2... dims) + -> multi_span +{ + static_assert(details::is_multi_span::value, + "Variadic as_multi_span() is for reshaping existing spans."); + using BoundsType = + typename multi_span::bounds_type; + auto tobounds = details::static_as_multi_span_helper(dims..., details::Sep{}); + details::verifyBoundsReshape(s.bounds(), tobounds); + return {s.data(), tobounds}; +} + +// convert a multi_span to a multi_span +template +multi_span as_bytes(multi_span s) GSL_NOEXCEPT +{ + static_assert(std::is_trivial>::value, + "The value_type of multi_span must be a trivial type."); + return {reinterpret_cast(s.data()), s.size_bytes()}; +} + +// convert a multi_span to a multi_span (a writeable byte multi_span) +// this is not currently a portable function that can be relied upon to work +// on all implementations. It should be considered an experimental extension +// to the standard GSL interface. +template +multi_span as_writeable_bytes(multi_span s) GSL_NOEXCEPT +{ + static_assert(std::is_trivial>::value, + "The value_type of multi_span must be a trivial type."); + return {reinterpret_cast(s.data()), s.size_bytes()}; +} + +// convert a multi_span to a multi_span +// this is not currently a portable function that can be relied upon to work +// on all implementations. It should be considered an experimental extension +// to the standard GSL interface. +template +constexpr auto +as_multi_span(multi_span s) GSL_NOEXCEPT -> multi_span< + const U, static_cast( + multi_span::bounds_type::static_size != dynamic_range + ? (static_cast( + multi_span::bounds_type::static_size) / + sizeof(U)) + : dynamic_range)> +{ + using ConstByteSpan = multi_span; + static_assert( + std::is_trivial>::value && + (ConstByteSpan::bounds_type::static_size == dynamic_range || + ConstByteSpan::bounds_type::static_size % narrow_cast(sizeof(U)) == 0), + "Target type must be a trivial type and its size must match the byte array size"); + + Expects((s.size_bytes() % narrow_cast(sizeof(U))) == 0 && + (s.size_bytes() / narrow_cast(sizeof(U))) < PTRDIFF_MAX); + return {reinterpret_cast(s.data()), + s.size_bytes() / narrow_cast(sizeof(U))}; +} + +// convert a multi_span to a multi_span +// this is not currently a portable function that can be relied upon to work +// on all implementations. It should be considered an experimental extension +// to the standard GSL interface. +template +constexpr auto as_multi_span(multi_span s) GSL_NOEXCEPT + -> multi_span( + multi_span::bounds_type::static_size != dynamic_range + ? static_cast( + multi_span::bounds_type::static_size) / + sizeof(U) + : dynamic_range)> +{ + using ByteSpan = multi_span; + static_assert( + std::is_trivial>::value && + (ByteSpan::bounds_type::static_size == dynamic_range || + ByteSpan::bounds_type::static_size % sizeof(U) == 0), + "Target type must be a trivial type and its size must match the byte array size"); + + Expects((s.size_bytes() % sizeof(U)) == 0); + return {reinterpret_cast(s.data()), + s.size_bytes() / narrow_cast(sizeof(U))}; +} + +template +constexpr auto as_multi_span(T* const& ptr, dim_t... args) + -> multi_span, Dimensions...> +{ + return {reinterpret_cast*>(ptr), + details::static_as_multi_span_helper>(args..., + details::Sep{})}; +} + +template +constexpr auto as_multi_span(T* arr, std::ptrdiff_t len) -> + typename details::SpanArrayTraits::type +{ + return {reinterpret_cast*>(arr), len}; +} + +template +constexpr auto as_multi_span(T (&arr)[N]) -> typename details::SpanArrayTraits::type +{ + return {arr}; +} + +template +constexpr multi_span as_multi_span(const std::array& arr) +{ + return {arr}; +} + +template +constexpr multi_span as_multi_span(const std::array&&) = delete; + +template +constexpr multi_span as_multi_span(std::array& arr) +{ + return {arr}; +} + +template +constexpr multi_span as_multi_span(T* begin, T* end) +{ + return {begin, end}; +} + +template +constexpr auto as_multi_span(Cont& arr) -> std::enable_if_t< + !details::is_multi_span>::value, + multi_span, dynamic_range>> +{ + Expects(arr.size() < PTRDIFF_MAX); + return {arr.data(), narrow_cast(arr.size())}; +} + +template +constexpr auto as_multi_span(Cont&& arr) -> std::enable_if_t< + !details::is_multi_span>::value, + multi_span, dynamic_range>> = delete; + +// from basic_string which doesn't have nonconst .data() member like other contiguous containers +template +constexpr auto as_multi_span(std::basic_string& str) + -> multi_span +{ + Expects(str.size() < PTRDIFF_MAX); + return {&str[0], narrow_cast(str.size())}; +} + +// strided_span is an extension that is not strictly part of the GSL at this time. +// It is kept here while the multidimensional interface is still being defined. +template +class strided_span +{ +public: + using bounds_type = strided_bounds; + using size_type = typename bounds_type::size_type; + using index_type = typename bounds_type::index_type; + using value_type = ValueType; + using const_value_type = std::add_const_t; + using pointer = std::add_pointer_t; + using reference = std::add_lvalue_reference_t; + using iterator = general_span_iterator; + using const_strided_span = strided_span; + using const_iterator = general_span_iterator; + using reverse_iterator = std::reverse_iterator; + using const_reverse_iterator = std::reverse_iterator; + using sliced_type = + std::conditional_t>; + +private: + pointer data_; + bounds_type bounds_; + + friend iterator; + friend const_iterator; + template + friend class strided_span; + +public: + // from raw data + constexpr strided_span(pointer ptr, size_type size, bounds_type bounds) + : data_(ptr), bounds_(std::move(bounds)) + { + Expects((bounds_.size() > 0 && ptr != nullptr) || bounds_.size() == 0); + // Bounds cross data boundaries + Expects(this->bounds().total_size() <= size); + (void) size; + } + + // from static array of size N + template + constexpr strided_span(value_type (&values)[N], bounds_type bounds) + : strided_span(values, N, std::move(bounds)) + { + } + + // from array view + template ::value, + typename = std::enable_if_t> + constexpr strided_span(multi_span av, bounds_type bounds) + : strided_span(av.data(), av.bounds().total_size(), std::move(bounds)) + { + } + + // convertible + template ::value>> + constexpr strided_span(const strided_span& other) + : data_(other.data_), bounds_(other.bounds_) + { + } + + // convert from bytes + template + constexpr strided_span< + typename std::enable_if::value, OtherValueType>::type, + Rank> + as_strided_span() const + { + static_assert((sizeof(OtherValueType) >= sizeof(value_type)) && + (sizeof(OtherValueType) % sizeof(value_type) == 0), + "OtherValueType should have a size to contain a multiple of ValueTypes"); + auto d = narrow_cast(sizeof(OtherValueType) / sizeof(value_type)); + + size_type size = this->bounds().total_size() / d; + return {const_cast(reinterpret_cast(this->data())), + size, + bounds_type{resize_extent(this->bounds().index_bounds(), d), + resize_stride(this->bounds().strides(), d)}}; + } + + constexpr strided_span section(index_type origin, index_type extents) const + { + size_type size = this->bounds().total_size() - this->bounds().linearize(origin); + return {&this->operator[](origin), size, + bounds_type{extents, details::make_stride(bounds())}}; + } + + constexpr reference operator[](const index_type& idx) const + { + return data_[bounds_.linearize(idx)]; + } + + template 1), typename Ret = std::enable_if_t> + constexpr Ret operator[](size_type idx) const + { + Expects(idx < bounds_.size()); // index is out of bounds of the array + const size_type ridx = idx * bounds_.stride(); + + // index is out of bounds of the underlying data + Expects(ridx < bounds_.total_size()); + return {data_ + ridx, bounds_.slice().total_size(), bounds_.slice()}; + } + + constexpr bounds_type bounds() const GSL_NOEXCEPT { return bounds_; } + + template + constexpr size_type extent() const GSL_NOEXCEPT + { + static_assert(Dim < Rank, + "dimension should be less than Rank (dimension count starts from 0)"); + return bounds_.template extent(); + } + + constexpr size_type size() const GSL_NOEXCEPT { return bounds_.size(); } + + constexpr pointer data() const GSL_NOEXCEPT { return data_; } + + constexpr explicit operator bool() const GSL_NOEXCEPT { return data_ != nullptr; } + + constexpr iterator begin() const { return iterator{this, true}; } + + constexpr iterator end() const { return iterator{this, false}; } + + constexpr const_iterator cbegin() const + { + return const_iterator{reinterpret_cast(this), true}; + } + + constexpr const_iterator cend() const + { + return const_iterator{reinterpret_cast(this), false}; + } + + constexpr reverse_iterator rbegin() const { return reverse_iterator{end()}; } + + constexpr reverse_iterator rend() const { return reverse_iterator{begin()}; } + + constexpr const_reverse_iterator crbegin() const { return const_reverse_iterator{cend()}; } + + constexpr const_reverse_iterator crend() const { return const_reverse_iterator{cbegin()}; } + + template , std::remove_cv_t>::value>> + constexpr bool + operator==(const strided_span& other) const GSL_NOEXCEPT + { + return bounds_.size() == other.bounds_.size() && + (data_ == other.data_ || std::equal(this->begin(), this->end(), other.begin())); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator!=(const strided_span& other) const GSL_NOEXCEPT + { + return !(*this == other); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator<(const strided_span& other) const GSL_NOEXCEPT + { + return std::lexicographical_compare(this->begin(), this->end(), other.begin(), other.end()); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator<=(const strided_span& other) const GSL_NOEXCEPT + { + return !(other < *this); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator>(const strided_span& other) const GSL_NOEXCEPT + { + return (other < *this); + } + + template , std::remove_cv_t>::value>> + constexpr bool + operator>=(const strided_span& other) const GSL_NOEXCEPT + { + return !(*this < other); + } + +private: + static index_type resize_extent(const index_type& extent, std::ptrdiff_t d) + { + // The last dimension of the array needs to contain a multiple of new type elements + Expects(extent[Rank - 1] >= d && (extent[Rank - 1] % d == 0)); + + index_type ret = extent; + ret[Rank - 1] /= d; + + return ret; + } + + template > + static index_type resize_stride(const index_type& strides, std::ptrdiff_t, void* = nullptr) + { + // Only strided arrays with regular strides can be resized + Expects(strides[Rank - 1] == 1); + + return strides; + } + + template 1), typename = std::enable_if_t> + static index_type resize_stride(const index_type& strides, std::ptrdiff_t d) + { + // Only strided arrays with regular strides can be resized + Expects(strides[Rank - 1] == 1); + // The strides must have contiguous chunks of + // memory that can contain a multiple of new type elements + Expects(strides[Rank - 2] >= d && (strides[Rank - 2] % d == 0)); + + for (std::size_t i = Rank - 1; i > 0; --i) { + // Only strided arrays with regular strides can be resized + Expects((strides[i - 1] >= strides[i]) && (strides[i - 1] % strides[i] == 0)); + } + + index_type ret = strides / d; + ret[Rank - 1] = 1; + + return ret; + } +}; + +template +class contiguous_span_iterator +{ +public: + using iterator_category = std::random_access_iterator_tag; + using value_type = typename Span::value_type; + using difference_type = std::ptrdiff_t; + using pointer = value_type*; + using reference = value_type&; + +private: + template + friend class multi_span; + + pointer data_; + const Span* m_validator; + void validateThis() const + { + // iterator is out of range of the array + Expects(data_ >= m_validator->data_ && data_ < m_validator->data_ + m_validator->size()); + } + contiguous_span_iterator(const Span* container, bool isbegin) + : data_(isbegin ? container->data_ : container->data_ + container->size()) + , m_validator(container) + { + } + +public: + reference operator*() const GSL_NOEXCEPT + { + validateThis(); + return *data_; + } + pointer operator->() const GSL_NOEXCEPT + { + validateThis(); + return data_; + } + contiguous_span_iterator& operator++() GSL_NOEXCEPT + { + ++data_; + return *this; + } + contiguous_span_iterator operator++(int) GSL_NOEXCEPT + { + auto ret = *this; + ++(*this); + return ret; + } + contiguous_span_iterator& operator--() GSL_NOEXCEPT + { + --data_; + return *this; + } + contiguous_span_iterator operator--(int) GSL_NOEXCEPT + { + auto ret = *this; + --(*this); + return ret; + } + contiguous_span_iterator operator+(difference_type n) const GSL_NOEXCEPT + { + contiguous_span_iterator ret{*this}; + return ret += n; + } + contiguous_span_iterator& operator+=(difference_type n) GSL_NOEXCEPT + { + data_ += n; + return *this; + } + contiguous_span_iterator operator-(difference_type n) const GSL_NOEXCEPT + { + contiguous_span_iterator ret{*this}; + return ret -= n; + } + contiguous_span_iterator& operator-=(difference_type n) GSL_NOEXCEPT { return *this += -n; } + difference_type operator-(const contiguous_span_iterator& rhs) const GSL_NOEXCEPT + { + Expects(m_validator == rhs.m_validator); + return data_ - rhs.data_; + } + reference operator[](difference_type n) const GSL_NOEXCEPT { return *(*this + n); } + bool operator==(const contiguous_span_iterator& rhs) const GSL_NOEXCEPT + { + Expects(m_validator == rhs.m_validator); + return data_ == rhs.data_; + } + bool operator!=(const contiguous_span_iterator& rhs) const GSL_NOEXCEPT + { + return !(*this == rhs); + } + bool operator<(const contiguous_span_iterator& rhs) const GSL_NOEXCEPT + { + Expects(m_validator == rhs.m_validator); + return data_ < rhs.data_; + } + bool operator<=(const contiguous_span_iterator& rhs) const GSL_NOEXCEPT + { + return !(rhs < *this); + } + bool operator>(const contiguous_span_iterator& rhs) const GSL_NOEXCEPT { return rhs < *this; } + bool operator>=(const contiguous_span_iterator& rhs) const GSL_NOEXCEPT + { + return !(rhs > *this); + } + void swap(contiguous_span_iterator& rhs) GSL_NOEXCEPT + { + std::swap(data_, rhs.data_); + std::swap(m_validator, rhs.m_validator); + } +}; + +template +contiguous_span_iterator operator+(typename contiguous_span_iterator::difference_type n, + const contiguous_span_iterator& rhs) GSL_NOEXCEPT +{ + return rhs + n; +} + +template +class general_span_iterator +{ +public: + using iterator_category = std::random_access_iterator_tag; + using value_type = typename Span::value_type; + using difference_type = std::ptrdiff_t; + using pointer = value_type*; + using reference = value_type&; + +private: + template + friend class strided_span; + + const Span* m_container; + typename Span::bounds_type::iterator m_itr; + general_span_iterator(const Span* container, bool isbegin) + : m_container(container) + , m_itr(isbegin ? m_container->bounds().begin() : m_container->bounds().end()) + { + } + +public: + reference operator*() GSL_NOEXCEPT { return (*m_container)[*m_itr]; } + pointer operator->() GSL_NOEXCEPT { return &(*m_container)[*m_itr]; } + general_span_iterator& operator++() GSL_NOEXCEPT + { + ++m_itr; + return *this; + } + general_span_iterator operator++(int) GSL_NOEXCEPT + { + auto ret = *this; + ++(*this); + return ret; + } + general_span_iterator& operator--() GSL_NOEXCEPT + { + --m_itr; + return *this; + } + general_span_iterator operator--(int) GSL_NOEXCEPT + { + auto ret = *this; + --(*this); + return ret; + } + general_span_iterator operator+(difference_type n) const GSL_NOEXCEPT + { + general_span_iterator ret{*this}; + return ret += n; + } + general_span_iterator& operator+=(difference_type n) GSL_NOEXCEPT + { + m_itr += n; + return *this; + } + general_span_iterator operator-(difference_type n) const GSL_NOEXCEPT + { + general_span_iterator ret{*this}; + return ret -= n; + } + general_span_iterator& operator-=(difference_type n) GSL_NOEXCEPT { return *this += -n; } + difference_type operator-(const general_span_iterator& rhs) const GSL_NOEXCEPT + { + Expects(m_container == rhs.m_container); + return m_itr - rhs.m_itr; + } + value_type operator[](difference_type n) const GSL_NOEXCEPT { return (*m_container)[m_itr[n]]; } + + bool operator==(const general_span_iterator& rhs) const GSL_NOEXCEPT + { + Expects(m_container == rhs.m_container); + return m_itr == rhs.m_itr; + } + bool operator!=(const general_span_iterator& rhs) const GSL_NOEXCEPT { return !(*this == rhs); } + bool operator<(const general_span_iterator& rhs) const GSL_NOEXCEPT + { + Expects(m_container == rhs.m_container); + return m_itr < rhs.m_itr; + } + bool operator<=(const general_span_iterator& rhs) const GSL_NOEXCEPT { return !(rhs < *this); } + bool operator>(const general_span_iterator& rhs) const GSL_NOEXCEPT { return rhs < *this; } + bool operator>=(const general_span_iterator& rhs) const GSL_NOEXCEPT { return !(rhs > *this); } + void swap(general_span_iterator& rhs) GSL_NOEXCEPT + { + std::swap(m_itr, rhs.m_itr); + std::swap(m_container, rhs.m_container); + } +}; + +template +general_span_iterator operator+(typename general_span_iterator::difference_type n, + const general_span_iterator& rhs) GSL_NOEXCEPT +{ + return rhs + n; +} + +} // namespace gsl + +#undef GSL_NOEXCEPT + +#ifdef _MSC_VER +#if _MSC_VER < 1910 + +#undef constexpr +#pragma pop_macro("constexpr") +#endif // _MSC_VER < 1910 + +#pragma warning(pop) + +#endif // _MSC_VER + +#if __GNUC__ > 6 +#pragma GCC diagnostic pop +#endif // __GNUC__ > 6 + +#endif // GSL_MULTI_SPAN_H diff --git a/include/gsl/pointers b/include/gsl/pointers new file mode 100644 index 0000000..69499d6 --- /dev/null +++ b/include/gsl/pointers @@ -0,0 +1,193 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_POINTERS_H +#define GSL_POINTERS_H + +#include // for Ensures, Expects + +#include // for forward +#include // for ptrdiff_t, nullptr_t, ostream, size_t +#include // for shared_ptr, unique_ptr +#include // for hash +#include // for enable_if_t, is_convertible, is_assignable + +#if defined(_MSC_VER) && _MSC_VER < 1910 +#pragma push_macro("constexpr") +#define constexpr /*constexpr*/ + +#endif // defined(_MSC_VER) && _MSC_VER < 1910 + +namespace gsl +{ + +// +// GSL.owner: ownership pointers +// +using std::unique_ptr; +using std::shared_ptr; + +// +// owner +// +// owner is designed as a bridge for code that must deal directly with owning pointers for some reason +// +// T must be a pointer type +// - disallow construction from any type other than pointer type +// +template ::value>> +using owner = T; + +// +// not_null +// +// Restricts a pointer or smart pointer to only hold non-null values. +// +// Has zero size overhead over T. +// +// If T is a pointer (i.e. T == U*) then +// - allow construction from U* +// - disallow construction from nullptr_t +// - disallow default construction +// - ensure construction from null U* fails +// - allow implicit conversion to U* +// +template +class not_null +{ +public: + static_assert(std::is_assignable::value, "T cannot be assigned nullptr."); + + template ::value>> + constexpr explicit not_null(U&& u) : ptr_(std::forward(u)) + { + Expects(ptr_ != nullptr); + } + + template ::value>> + constexpr explicit not_null(T u) : ptr_(u) + { + Expects(ptr_ != nullptr); + } + + template ::value>> + constexpr not_null(const not_null& other) : not_null(other.get()) + { + } + + not_null(not_null&& other) = default; + not_null(const not_null& other) = default; + not_null& operator=(const not_null& other) = default; + + constexpr T get() const + { + Ensures(ptr_ != nullptr); + return ptr_; + } + + constexpr operator T() const { return get(); } + constexpr T operator->() const { return get(); } + constexpr decltype(auto) operator*() const { return *get(); } + + // prevents compilation when someone attempts to assign a null pointer constant + not_null(std::nullptr_t) = delete; + not_null& operator=(std::nullptr_t) = delete; + + // unwanted operators...pointers only point to single objects! + not_null& operator++() = delete; + not_null& operator--() = delete; + not_null operator++(int) = delete; + not_null operator--(int) = delete; + not_null& operator+=(std::ptrdiff_t) = delete; + not_null& operator-=(std::ptrdiff_t) = delete; + void operator[](std::ptrdiff_t) const = delete; + +private: + T ptr_; +}; + +template +std::ostream& operator<<(std::ostream& os, const not_null& val) +{ + os << val.get(); + return os; +} + +template +auto operator==(const not_null& lhs, const not_null& rhs) -> decltype(lhs.get() == rhs.get()) +{ + return lhs.get() == rhs.get(); +} + +template +auto operator!=(const not_null& lhs, const not_null& rhs) -> decltype(lhs.get() != rhs.get()) +{ + return lhs.get() != rhs.get(); +} + +template +auto operator<(const not_null& lhs, const not_null& rhs) -> decltype(lhs.get() < rhs.get()) +{ + return lhs.get() < rhs.get(); +} + +template +auto operator<=(const not_null& lhs, const not_null& rhs) -> decltype(lhs.get() <= rhs.get()) +{ + return lhs.get() <= rhs.get(); +} + +template +auto operator>(const not_null& lhs, const not_null& rhs) -> decltype(lhs.get() > rhs.get()) +{ + return lhs.get() > rhs.get(); +} + +template +auto operator>=(const not_null& lhs, const not_null& rhs) -> decltype(lhs.get() >= rhs.get()) +{ + return lhs.get() >= rhs.get(); +} + +// more unwanted operators +template +std::ptrdiff_t operator-(const not_null&, const not_null&) = delete; +template +not_null operator-(const not_null&, std::ptrdiff_t) = delete; +template +not_null operator+(const not_null&, std::ptrdiff_t) = delete; +template +not_null operator+(std::ptrdiff_t, const not_null&) = delete; + +} // namespace gsl + +namespace std +{ +template +struct hash> +{ + std::size_t operator()(const gsl::not_null& value) const { return hash{}(value); } +}; + +} // namespace std + +#if defined(_MSC_VER) && _MSC_VER < 1910 +#undef constexpr +#pragma pop_macro("constexpr") + +#endif // defined(_MSC_VER) && _MSC_VER < 1910 + +#endif // GSL_POINTERS_H diff --git a/include/gsl/span b/include/gsl/span new file mode 100644 index 0000000..2fa9cc5 --- /dev/null +++ b/include/gsl/span @@ -0,0 +1,766 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_SPAN_H +#define GSL_SPAN_H + +#include // for Expects +#include // for byte +#include // for narrow_cast, narrow + +#include // for lexicographical_compare +#include // for array +#include // for ptrdiff_t, size_t, nullptr_t +#include // for reverse_iterator, distance, random_access_... +#include +#include +#include // for enable_if_t, declval, is_convertible, inte... +#include + +#ifdef _MSC_VER +#pragma warning(push) + +// turn off some warnings that are noisy about our Expects statements +#pragma warning(disable : 4127) // conditional expression is constant +#pragma warning(disable : 4702) // unreachable code + +// blanket turn off warnings from CppCoreCheck for now +// so people aren't annoyed by them when running the tool. +// more targeted suppressions will be added in a future update to the GSL +#pragma warning(disable : 26481 26482 26483 26485 26490 26491 26492 26493 26495) + +#if _MSC_VER < 1910 +#pragma push_macro("constexpr") +#define constexpr /*constexpr*/ +#define GSL_USE_STATIC_CONSTEXPR_WORKAROUND + +#endif // _MSC_VER < 1910 +#else // _MSC_VER + +// See if we have enough C++17 power to use a static constexpr data member +// without needing an out-of-line definition +#if !(defined(__cplusplus) && (__cplusplus >= 201703L)) +#define GSL_USE_STATIC_CONSTEXPR_WORKAROUND +#endif // !(defined(__cplusplus) && (__cplusplus >= 201703L)) + +#endif // _MSC_VER + +// GCC 7 does not like the signed unsigned missmatch (size_t ptrdiff_t) +// While there is a conversion from signed to unsigned, it happens at +// compiletime, so the compiler wouldn't have to warn indiscriminently, but +// could check if the source value actually doesn't fit into the target type +// and only warn in those cases. +#if __GNUC__ > 6 +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wsign-conversion" +#endif + +namespace gsl +{ + +// [views.constants], constants +constexpr const std::ptrdiff_t dynamic_extent = -1; + +template +class span; + +// implementation details +namespace details +{ + template + struct is_span_oracle : std::false_type + { + }; + + template + struct is_span_oracle> : std::true_type + { + }; + + template + struct is_span : public is_span_oracle> + { + }; + + template + struct is_std_array_oracle : std::false_type + { + }; + + template + struct is_std_array_oracle> : std::true_type + { + }; + + template + struct is_std_array : public is_std_array_oracle> + { + }; + + template + struct is_allowed_extent_conversion + : public std::integral_constant + { + }; + + template + struct is_allowed_element_type_conversion + : public std::integral_constant::value> + { + }; + + template + class span_iterator + { + using element_type_ = typename Span::element_type; + + public: + +#ifdef _MSC_VER + // Tell Microsoft standard library that span_iterators are checked. + using _Unchecked_type = typename Span::pointer; +#endif + + using iterator_category = std::random_access_iterator_tag; + using value_type = std::remove_cv_t; + using difference_type = typename Span::index_type; + + using reference = std::conditional_t&; + using pointer = std::add_pointer_t; + + span_iterator() = default; + + constexpr span_iterator(const Span* span, typename Span::index_type idx) noexcept + : span_(span), index_(idx) + {} + + friend span_iterator; + template* = nullptr> + constexpr span_iterator(const span_iterator& other) noexcept + : span_iterator(other.span_, other.index_) + { + } + + constexpr reference operator*() const + { + Expects(index_ != span_->size()); + return *(span_->data() + index_); + } + + constexpr pointer operator->() const + { + Expects(index_ != span_->size()); + return span_->data() + index_; + } + + constexpr span_iterator& operator++() + { + Expects(0 <= index_ && index_ != span_->size()); + ++index_; + return *this; + } + + constexpr span_iterator operator++(int) + { + auto ret = *this; + ++(*this); + return ret; + } + + constexpr span_iterator& operator--() + { + Expects(index_ != 0 && index_ <= span_->size()); + --index_; + return *this; + } + + constexpr span_iterator operator--(int) + { + auto ret = *this; + --(*this); + return ret; + } + + constexpr span_iterator operator+(difference_type n) const + { + auto ret = *this; + return ret += n; + } + + friend constexpr span_iterator operator+(difference_type n, span_iterator const& rhs) + { + return rhs + n; + } + + constexpr span_iterator& operator+=(difference_type n) + { + Expects((index_ + n) >= 0 && (index_ + n) <= span_->size()); + index_ += n; + return *this; + } + + constexpr span_iterator operator-(difference_type n) const + { + auto ret = *this; + return ret -= n; + } + + constexpr span_iterator& operator-=(difference_type n) { return *this += -n; } + + constexpr difference_type operator-(span_iterator rhs) const + { + Expects(span_ == rhs.span_); + return index_ - rhs.index_; + } + + constexpr reference operator[](difference_type n) const + { + return *(*this + n); + } + + constexpr friend bool operator==(span_iterator lhs, + span_iterator rhs) noexcept + { + return lhs.span_ == rhs.span_ && lhs.index_ == rhs.index_; + } + + constexpr friend bool operator!=(span_iterator lhs, + span_iterator rhs) noexcept + { + return !(lhs == rhs); + } + + constexpr friend bool operator<(span_iterator lhs, + span_iterator rhs) noexcept + { + return lhs.index_ < rhs.index_; + } + + constexpr friend bool operator<=(span_iterator lhs, + span_iterator rhs) noexcept + { + return !(rhs < lhs); + } + + constexpr friend bool operator>(span_iterator lhs, + span_iterator rhs) noexcept + { + return rhs < lhs; + } + + constexpr friend bool operator>=(span_iterator lhs, + span_iterator rhs) noexcept + { + return !(rhs > lhs); + } + +#ifdef _MSC_VER + // MSVC++ iterator debugging support; allows STL algorithms in 15.8+ + // to unwrap span_iterator to a pointer type after a range check in STL + // algorithm calls + friend constexpr void _Verify_range(span_iterator lhs, + span_iterator rhs) noexcept + { // test that [lhs, rhs) forms a valid range inside an STL algorithm + Expects(lhs.span_ == rhs.span_ // range spans have to match + && lhs.index_ <= rhs.index_); // range must not be transposed + } + + constexpr void _Verify_offset(const difference_type n) const noexcept + { // test that the iterator *this + n is a valid range in an STL + // algorithm call + Expects((index_ + n) >= 0 && (index_ + n) <= span_->size()); + } + + constexpr pointer _Unwrapped() const noexcept + { // after seeking *this to a high water mark, or using one of the + // _Verify_xxx functions above, unwrap this span_iterator to a raw + // pointer + return span_->data() + index_; + } + + // Tell the STL that span_iterator should not be unwrapped if it can't + // validate in advance, even in release / optimized builds: +#if defined(GSL_USE_STATIC_CONSTEXPR_WORKAROUND) + static constexpr const bool _Unwrap_when_unverified = false; +#else + static constexpr bool _Unwrap_when_unverified = false; +#endif + constexpr void _Seek_to(const pointer p) noexcept + { // adjust the position of *this to previously verified location p + // after _Unwrapped + index_ = p - span_->data(); + } +#endif + + protected: + const Span* span_ = nullptr; + std::ptrdiff_t index_ = 0; + }; + + template + class extent_type + { + public: + using index_type = std::ptrdiff_t; + + static_assert(Ext >= 0, "A fixed-size span must be >= 0 in size."); + + constexpr extent_type() noexcept {} + + template + constexpr extent_type(extent_type ext) + { + static_assert(Other == Ext || Other == dynamic_extent, + "Mismatch between fixed-size extent and size of initializing data."); + Expects(ext.size() == Ext); + } + + constexpr extent_type(index_type size) { Expects(size == Ext); } + + constexpr index_type size() const noexcept { return Ext; } + }; + + template <> + class extent_type + { + public: + using index_type = std::ptrdiff_t; + + template + explicit constexpr extent_type(extent_type ext) : size_(ext.size()) + { + } + + explicit constexpr extent_type(index_type size) : size_(size) { Expects(size >= 0); } + + constexpr index_type size() const noexcept { return size_; } + + private: + index_type size_; + }; + + template + struct calculate_subspan_type + { + using type = span; + }; +} // namespace details + +// [span], class template span +template +class span +{ +public: + // constants and types + using element_type = ElementType; + using value_type = std::remove_cv_t; + using index_type = std::ptrdiff_t; + using pointer = element_type*; + using reference = element_type&; + + using iterator = details::span_iterator, false>; + using const_iterator = details::span_iterator, true>; + using reverse_iterator = std::reverse_iterator; + using const_reverse_iterator = std::reverse_iterator; + + using size_type = index_type; + +#if defined(GSL_USE_STATIC_CONSTEXPR_WORKAROUND) + static constexpr const index_type extent { Extent }; +#else + static constexpr index_type extent { Extent }; +#endif + + // [span.cons], span constructors, copy, assignment, and destructor + template " SFINAE, + // since "std::enable_if_t" is ill-formed when Extent is greater than 0. + class = std::enable_if_t<(Dependent || Extent <= 0)>> + constexpr span() noexcept : storage_(nullptr, details::extent_type<0>()) + { + } + + constexpr span(pointer ptr, index_type count) : storage_(ptr, count) {} + + constexpr span(pointer firstElem, pointer lastElem) + : storage_(firstElem, std::distance(firstElem, lastElem)) + { + } + + template + constexpr span(element_type (&arr)[N]) noexcept + : storage_(KnownNotNull{&arr[0]}, details::extent_type()) + { + } + + template > + constexpr span(std::array& arr) noexcept + : storage_(&arr[0], details::extent_type()) + { + } + + template + constexpr span(const std::array, N>& arr) noexcept + : storage_(&arr[0], details::extent_type()) + { + } + + // NB: the SFINAE here uses .data() as a incomplete/imperfect proxy for the requirement + // on Container to be a contiguous sequence container. + template ::value && !details::is_std_array::value && + std::is_convertible::value && + std::is_convertible().data())>::value>> + constexpr span(Container& cont) : span(cont.data(), narrow(cont.size())) + { + } + + template ::value && !details::is_span::value && + std::is_convertible::value && + std::is_convertible().data())>::value>> + constexpr span(const Container& cont) : span(cont.data(), narrow(cont.size())) + { + } + + constexpr span(const span& other) noexcept = default; + + template < + class OtherElementType, std::ptrdiff_t OtherExtent, + class = std::enable_if_t< + details::is_allowed_extent_conversion::value && + details::is_allowed_element_type_conversion::value>> + constexpr span(const span& other) + : storage_(other.data(), details::extent_type(other.size())) + { + } + + ~span() noexcept = default; + constexpr span& operator=(const span& other) noexcept = default; + + // [span.sub], span subviews + template + constexpr span first() const + { + Expects(Count >= 0 && Count <= size()); + return {data(), Count}; + } + + template + constexpr span last() const + { + Expects(Count >= 0 && size() - Count >= 0); + return {data() + (size() - Count), Count}; + } + + template + constexpr auto subspan() const -> typename details::calculate_subspan_type::type + { + Expects((Offset >= 0 && size() - Offset >= 0) && + (Count == dynamic_extent || (Count >= 0 && Offset + Count <= size()))); + + return {data() + Offset, Count == dynamic_extent ? size() - Offset : Count}; + } + + constexpr span first(index_type count) const + { + Expects(count >= 0 && count <= size()); + return {data(), count}; + } + + constexpr span last(index_type count) const + { + return make_subspan(size() - count, dynamic_extent, subspan_selector{}); + } + + constexpr span subspan(index_type offset, + index_type count = dynamic_extent) const + { + return make_subspan(offset, count, subspan_selector{}); + } + + + // [span.obs], span observers + constexpr index_type size() const noexcept { return storage_.size(); } + constexpr index_type size_bytes() const noexcept + { + return size() * narrow_cast(sizeof(element_type)); + } + constexpr bool empty() const noexcept { return size() == 0; } + + // [span.elem], span element access + constexpr reference operator[](index_type idx) const + { + Expects(idx >= 0 && idx < storage_.size()); + return data()[idx]; + } + + constexpr reference at(index_type idx) const { return this->operator[](idx); } + constexpr reference operator()(index_type idx) const { return this->operator[](idx); } + constexpr pointer data() const noexcept { return storage_.data(); } + + // [span.iter], span iterator support + constexpr iterator begin() const noexcept { return {this, 0}; } + constexpr iterator end() const noexcept { return {this, size()}; } + + constexpr const_iterator cbegin() const noexcept { return {this, 0}; } + constexpr const_iterator cend() const noexcept { return {this, size()}; } + + constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator{end()}; } + constexpr reverse_iterator rend() const noexcept { return reverse_iterator{begin()}; } + + constexpr const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator{cend()}; } + constexpr const_reverse_iterator crend() const noexcept { return const_reverse_iterator{cbegin()}; } + +#ifdef _MSC_VER + // Tell MSVC how to unwrap spans in range-based-for + constexpr pointer _Unchecked_begin() const noexcept { return data(); } + constexpr pointer _Unchecked_end() const noexcept { return data() + size(); } +#endif // _MSC_VER + +private: + + // Needed to remove unnecessary null check in subspans + struct KnownNotNull + { + pointer p; + }; + + // this implementation detail class lets us take advantage of the + // empty base class optimization to pay for only storage of a single + // pointer in the case of fixed-size spans + template + class storage_type : public ExtentType + { + public: + // KnownNotNull parameter is needed to remove unnecessary null check + // in subspans and constructors from arrays + template + constexpr storage_type(KnownNotNull data, OtherExtentType ext) : ExtentType(ext), data_(data.p) + { + Expects(ExtentType::size() >= 0); + } + + + template + constexpr storage_type(pointer data, OtherExtentType ext) : ExtentType(ext), data_(data) + { + Expects(ExtentType::size() >= 0); + Expects(data || ExtentType::size() == 0); + } + + constexpr pointer data() const noexcept { return data_; } + + private: + pointer data_; + }; + + storage_type> storage_; + + // The rest is needed to remove unnecessary null check + // in subspans and constructors from arrays + constexpr span(KnownNotNull ptr, index_type count) : storage_(ptr, count) {} + + template + class subspan_selector {}; + + template + span make_subspan(index_type offset, + index_type count, + subspan_selector) const + { + span tmp(*this); + return tmp.subspan(offset, count); + } + + span make_subspan(index_type offset, + index_type count, + subspan_selector) const + { + Expects(offset >= 0 && size() - offset >= 0); + if (count == dynamic_extent) + { + return { KnownNotNull{ data() + offset }, size() - offset }; + } + + Expects(count >= 0 && size() - offset >= count); + return { KnownNotNull{ data() + offset }, count }; + } +}; + +#if defined(GSL_USE_STATIC_CONSTEXPR_WORKAROUND) +template +constexpr const typename span::index_type span::extent; +#endif + + +// [span.comparison], span comparison operators +template +constexpr bool operator==(span l, + span r) +{ + return std::equal(l.begin(), l.end(), r.begin(), r.end()); +} + +template +constexpr bool operator!=(span l, + span r) +{ + return !(l == r); +} + +template +constexpr bool operator<(span l, + span r) +{ + return std::lexicographical_compare(l.begin(), l.end(), r.begin(), r.end()); +} + +template +constexpr bool operator<=(span l, + span r) +{ + return !(l > r); +} + +template +constexpr bool operator>(span l, + span r) +{ + return r < l; +} + +template +constexpr bool operator>=(span l, + span r) +{ + return !(l < r); +} + +namespace details +{ + // if we only supported compilers with good constexpr support then + // this pair of classes could collapse down to a constexpr function + + // we should use a narrow_cast<> to go to std::size_t, but older compilers may not see it as + // constexpr + // and so will fail compilation of the template + template + struct calculate_byte_size + : std::integral_constant(sizeof(ElementType) * + static_cast(Extent))> + { + }; + + template + struct calculate_byte_size + : std::integral_constant + { + }; +} + +// [span.objectrep], views of object representation +template +span::value> +as_bytes(span s) noexcept +{ + return {reinterpret_cast(s.data()), s.size_bytes()}; +} + +template ::value>> +span::value> +as_writeable_bytes(span s) noexcept +{ + return {reinterpret_cast(s.data()), s.size_bytes()}; +} + +// +// make_span() - Utility functions for creating spans +// +template +constexpr span make_span(ElementType* ptr, typename span::index_type count) +{ + return span(ptr, count); +} + +template +constexpr span make_span(ElementType* firstElem, ElementType* lastElem) +{ + return span(firstElem, lastElem); +} + +template +constexpr span make_span(ElementType (&arr)[N]) noexcept +{ + return span(arr); +} + +template +constexpr span make_span(Container& cont) +{ + return span(cont); +} + +template +constexpr span make_span(const Container& cont) +{ + return span(cont); +} + +template +constexpr span make_span(Ptr& cont, std::ptrdiff_t count) +{ + return span(cont, count); +} + +template +constexpr span make_span(Ptr& cont) +{ + return span(cont); +} + +// Specialization of gsl::at for span +template +constexpr ElementType& at(span s, index i) +{ + // No bounds checking here because it is done in span::operator[] called below + return s[i]; +} + +} // namespace gsl + +#ifdef _MSC_VER +#if _MSC_VER < 1910 +#undef constexpr +#pragma pop_macro("constexpr") + +#endif // _MSC_VER < 1910 + +#pragma warning(pop) +#endif // _MSC_VER + +#if __GNUC__ > 6 +#pragma GCC diagnostic pop +#endif // __GNUC__ > 6 + +#endif // GSL_SPAN_H diff --git a/include/gsl/string_span b/include/gsl/string_span new file mode 100644 index 0000000..c08f246 --- /dev/null +++ b/include/gsl/string_span @@ -0,0 +1,730 @@ +/////////////////////////////////////////////////////////////////////////////// +// +// Copyright (c) 2015 Microsoft Corporation. All rights reserved. +// +// This code is licensed under the MIT License (MIT). +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef GSL_STRING_SPAN_H +#define GSL_STRING_SPAN_H + +#include // for Ensures, Expects +#include // for narrow_cast +#include // for operator!=, operator==, dynamic_extent + +#include // for equal, lexicographical_compare +#include // for array +#include // for ptrdiff_t, size_t, nullptr_t +#include // for PTRDIFF_MAX +#include +#include // for basic_string, allocator, char_traits +#include // for declval, is_convertible, enable_if_t, add_... + +#ifdef _MSC_VER +#pragma warning(push) + +// blanket turn off warnings from CppCoreCheck for now +// so people aren't annoyed by them when running the tool. +// more targeted suppressions will be added in a future update to the GSL +#pragma warning(disable : 26481 26482 26483 26485 26490 26491 26492 26493 26495) + +#if _MSC_VER < 1910 +#pragma push_macro("constexpr") +#define constexpr /*constexpr*/ + +#endif // _MSC_VER < 1910 +#endif // _MSC_VER + +// In order to test the library, we need it to throw exceptions that we can catch +#ifdef GSL_THROW_ON_CONTRACT_VIOLATION +#define GSL_NOEXCEPT /*noexcept*/ +#else +#define GSL_NOEXCEPT noexcept +#endif // GSL_THROW_ON_CONTRACT_VIOLATION + +namespace gsl +{ +// +// czstring and wzstring +// +// These are "tag" typedefs for C-style strings (i.e. null-terminated character arrays) +// that allow static analysis to help find bugs. +// +// There are no additional features/semantics that we can find a way to add inside the +// type system for these types that will not either incur significant runtime costs or +// (sometimes needlessly) break existing programs when introduced. +// + +template +using basic_zstring = CharT*; + +template +using czstring = basic_zstring; + +template +using cwzstring = basic_zstring; + +template +using cu16zstring = basic_zstring; + +template +using cu32zstring = basic_zstring; + +template +using zstring = basic_zstring; + +template +using wzstring = basic_zstring; + +template +using u16zstring = basic_zstring; + +template +using u32zstring = basic_zstring; + +namespace details +{ + template + std::ptrdiff_t string_length(const CharT* str, std::ptrdiff_t n) + { + if (str == nullptr || n <= 0) return 0; + + const span str_span{str, n}; + + std::ptrdiff_t len = 0; + while (len < n && str_span[len]) len++; + + return len; + } +} + +// +// ensure_sentinel() +// +// Provides a way to obtain an span from a contiguous sequence +// that ends with a (non-inclusive) sentinel value. +// +// Will fail-fast if sentinel cannot be found before max elements are examined. +// +template +span ensure_sentinel(T* seq, std::ptrdiff_t max = PTRDIFF_MAX) +{ + auto cur = seq; + while ((cur - seq) < max && *cur != Sentinel) ++cur; + Ensures(*cur == Sentinel); + return {seq, cur - seq}; +} + +// +// ensure_z - creates a span for a zero terminated strings. +// Will fail fast if a null-terminator cannot be found before +// the limit of size_type. +// +template +span ensure_z(CharT* const& sz, std::ptrdiff_t max = PTRDIFF_MAX) +{ + return ensure_sentinel(sz, max); +} + +template +span ensure_z(CharT (&sz)[N]) +{ + return ensure_z(&sz[0], static_cast(N)); +} + +template +span::type, dynamic_extent> +ensure_z(Cont& cont) +{ + return ensure_z(cont.data(), static_cast(cont.size())); +} + +template +class basic_string_span; + +namespace details +{ + template + struct is_basic_string_span_oracle : std::false_type + { + }; + + template + struct is_basic_string_span_oracle> : std::true_type + { + }; + + template + struct is_basic_string_span : is_basic_string_span_oracle> + { + }; +} + +// +// string_span and relatives +// +template +class basic_string_span +{ +public: + using element_type = CharT; + using pointer = std::add_pointer_t; + using reference = std::add_lvalue_reference_t; + using const_reference = std::add_lvalue_reference_t>; + using impl_type = span; + + using index_type = typename impl_type::index_type; + using iterator = typename impl_type::iterator; + using const_iterator = typename impl_type::const_iterator; + using reverse_iterator = typename impl_type::reverse_iterator; + using const_reverse_iterator = typename impl_type::const_reverse_iterator; + + // default (empty) + constexpr basic_string_span() GSL_NOEXCEPT = default; + + // copy + constexpr basic_string_span(const basic_string_span& other) GSL_NOEXCEPT = default; + + // assign + constexpr basic_string_span& operator=(const basic_string_span& other) GSL_NOEXCEPT = default; + + constexpr basic_string_span(pointer ptr, index_type length) : span_(ptr, length) {} + constexpr basic_string_span(pointer firstElem, pointer lastElem) : span_(firstElem, lastElem) {} + + // From static arrays - if 0-terminated, remove 0 from the view + // All other containers allow 0s within the length, so we do not remove them + template + constexpr basic_string_span(element_type (&arr)[N]) : span_(remove_z(arr)) + { + } + + template > + constexpr basic_string_span(std::array& arr) GSL_NOEXCEPT : span_(arr) + { + } + + template > + constexpr basic_string_span(const std::array& arr) GSL_NOEXCEPT + : span_(arr) + { + } + + // Container signature should work for basic_string after C++17 version exists + template + constexpr basic_string_span(std::basic_string& str) + : span_(&str[0], narrow_cast(str.length())) + { + } + + template + constexpr basic_string_span(const std::basic_string& str) + : span_(&str[0], str.length()) + { + } + + // from containers. Containers must have a pointer type and data() function signatures + template ::value && + std::is_convertible::value && + std::is_convertible().data())>::value>> + constexpr basic_string_span(Container& cont) : span_(cont) + { + } + + template ::value && + std::is_convertible::value && + std::is_convertible().data())>::value>> + constexpr basic_string_span(const Container& cont) : span_(cont) + { + } + + // from string_span + template < + class OtherValueType, std::ptrdiff_t OtherExtent, + class = std::enable_if_t::impl_type, impl_type>::value>> + constexpr basic_string_span(basic_string_span other) + : span_(other.data(), other.length()) + { + } + + template + constexpr basic_string_span first() const + { + return {span_.template first()}; + } + + constexpr basic_string_span first(index_type count) const + { + return {span_.first(count)}; + } + + template + constexpr basic_string_span last() const + { + return {span_.template last()}; + } + + constexpr basic_string_span last(index_type count) const + { + return {span_.last(count)}; + } + + template + constexpr basic_string_span subspan() const + { + return {span_.template subspan()}; + } + + constexpr basic_string_span + subspan(index_type offset, index_type count = dynamic_extent) const + { + return {span_.subspan(offset, count)}; + } + + constexpr reference operator[](index_type idx) const { return span_[idx]; } + constexpr reference operator()(index_type idx) const { return span_[idx]; } + + constexpr pointer data() const { return span_.data(); } + + constexpr index_type length() const GSL_NOEXCEPT { return span_.size(); } + constexpr index_type size() const GSL_NOEXCEPT { return span_.size(); } + constexpr index_type size_bytes() const GSL_NOEXCEPT { return span_.size_bytes(); } + constexpr index_type length_bytes() const GSL_NOEXCEPT { return span_.length_bytes(); } + constexpr bool empty() const GSL_NOEXCEPT { return size() == 0; } + + constexpr iterator begin() const GSL_NOEXCEPT { return span_.begin(); } + constexpr iterator end() const GSL_NOEXCEPT { return span_.end(); } + + constexpr const_iterator cbegin() const GSL_NOEXCEPT { return span_.cbegin(); } + constexpr const_iterator cend() const GSL_NOEXCEPT { return span_.cend(); } + + constexpr reverse_iterator rbegin() const GSL_NOEXCEPT { return span_.rbegin(); } + constexpr reverse_iterator rend() const GSL_NOEXCEPT { return span_.rend(); } + + constexpr const_reverse_iterator crbegin() const GSL_NOEXCEPT { return span_.crbegin(); } + constexpr const_reverse_iterator crend() const GSL_NOEXCEPT { return span_.crend(); } + +private: + static impl_type remove_z(pointer const& sz, std::ptrdiff_t max) + { + return {sz, details::string_length(sz, max)}; + } + + template + static impl_type remove_z(element_type (&sz)[N]) + { + return remove_z(&sz[0], narrow_cast(N)); + } + + impl_type span_; +}; + +template +using string_span = basic_string_span; + +template +using cstring_span = basic_string_span; + +template +using wstring_span = basic_string_span; + +template +using cwstring_span = basic_string_span; + +template +using u16string_span = basic_string_span; + +template +using cu16string_span = basic_string_span; + +template +using u32string_span = basic_string_span; + +template +using cu32string_span = basic_string_span; + +// +// to_string() allow (explicit) conversions from string_span to string +// + +template +std::basic_string::type> +to_string(basic_string_span view) +{ + return {view.data(), static_cast(view.length())}; +} + +template , + typename Allocator = std::allocator, typename gCharT, std::ptrdiff_t Extent> +std::basic_string to_basic_string(basic_string_span view) +{ + return {view.data(), static_cast(view.length())}; +} + +template +basic_string_span::value> +as_bytes(basic_string_span s) noexcept +{ + return { reinterpret_cast(s.data()), s.size_bytes() }; +} + +template ::value>> +basic_string_span::value> +as_writeable_bytes(basic_string_span s) noexcept +{ + return {reinterpret_cast(s.data()), s.size_bytes()}; +} + +// zero-terminated string span, used to convert +// zero-terminated spans to legacy strings +template +class basic_zstring_span +{ +public: + using value_type = CharT; + using const_value_type = std::add_const_t; + + using pointer = std::add_pointer_t; + using const_pointer = std::add_pointer_t; + + using zstring_type = basic_zstring; + using const_zstring_type = basic_zstring; + + using impl_type = span; + using string_span_type = basic_string_span; + + constexpr basic_zstring_span(impl_type s) GSL_NOEXCEPT : span_(s) + { + // expects a zero-terminated span + Expects(s[s.size() - 1] == '\0'); + } + + // copy + constexpr basic_zstring_span(const basic_zstring_span& other) = default; + + // move + constexpr basic_zstring_span(basic_zstring_span&& other) = default; + + // assign + constexpr basic_zstring_span& operator=(const basic_zstring_span& other) = default; + + // move assign + constexpr basic_zstring_span& operator=(basic_zstring_span&& other) = default; + + constexpr bool empty() const GSL_NOEXCEPT { return span_.size() == 0; } + + constexpr string_span_type as_string_span() const GSL_NOEXCEPT + { + auto sz = span_.size(); + return { span_.data(), sz > 1 ? sz - 1 : 0 }; + } + constexpr string_span_type ensure_z() const GSL_NOEXCEPT { return gsl::ensure_z(span_); } + + constexpr const_zstring_type assume_z() const GSL_NOEXCEPT { return span_.data(); } + +private: + impl_type span_; +}; + +template +using zstring_span = basic_zstring_span; + +template +using wzstring_span = basic_zstring_span; + +template +using u16zstring_span = basic_zstring_span; + +template +using u32zstring_span = basic_zstring_span; + +template +using czstring_span = basic_zstring_span; + +template +using cwzstring_span = basic_zstring_span; + +template +using cu16zstring_span = basic_zstring_span; + +template +using cu32zstring_span = basic_zstring_span; + +// operator == +template ::value || + std::is_convertible>>::value>> +bool operator==(const gsl::basic_string_span& one, const T& other) GSL_NOEXCEPT +{ + const gsl::basic_string_span> tmp(other); + return std::equal(one.begin(), one.end(), tmp.begin(), tmp.end()); +} + +template ::value && + std::is_convertible>>::value>> +bool operator==(const T& one, const gsl::basic_string_span& other) GSL_NOEXCEPT +{ + gsl::basic_string_span> tmp(one); + return std::equal(tmp.begin(), tmp.end(), other.begin(), other.end()); +} + +// operator != +template , Extent>>::value>> +bool operator!=(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + return !(one == other); +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename = std::enable_if_t< + std::is_convertible, Extent>>::value && + !gsl::details::is_basic_string_span::value>> +bool operator!=(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + return !(one == other); +} + +// operator< +template , Extent>>::value>> +bool operator<(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + const gsl::basic_string_span, Extent> tmp(other); + return std::lexicographical_compare(one.begin(), one.end(), tmp.begin(), tmp.end()); +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename = std::enable_if_t< + std::is_convertible, Extent>>::value && + !gsl::details::is_basic_string_span::value>> +bool operator<(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + gsl::basic_string_span, Extent> tmp(one); + return std::lexicographical_compare(tmp.begin(), tmp.end(), other.begin(), other.end()); +} + +#ifndef _MSC_VER + +// VS treats temp and const containers as convertible to basic_string_span, +// so the cases below are already covered by the previous operators + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename DataType = typename T::value_type, + typename = std::enable_if_t< + !gsl::details::is_span::value && !gsl::details::is_basic_string_span::value && + std::is_convertible::value && + std::is_same().size(), *std::declval().data())>, + DataType>::value>> +bool operator<(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + gsl::basic_string_span, Extent> tmp(other); + return std::lexicographical_compare(one.begin(), one.end(), tmp.begin(), tmp.end()); +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename DataType = typename T::value_type, + typename = std::enable_if_t< + !gsl::details::is_span::value && !gsl::details::is_basic_string_span::value && + std::is_convertible::value && + std::is_same().size(), *std::declval().data())>, + DataType>::value>> +bool operator<(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + gsl::basic_string_span, Extent> tmp(one); + return std::lexicographical_compare(tmp.begin(), tmp.end(), other.begin(), other.end()); +} +#endif + +// operator <= +template , Extent>>::value>> +bool operator<=(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + return !(other < one); +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename = std::enable_if_t< + std::is_convertible, Extent>>::value && + !gsl::details::is_basic_string_span::value>> +bool operator<=(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + return !(other < one); +} + +#ifndef _MSC_VER + +// VS treats temp and const containers as convertible to basic_string_span, +// so the cases below are already covered by the previous operators + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename DataType = typename T::value_type, + typename = std::enable_if_t< + !gsl::details::is_span::value && !gsl::details::is_basic_string_span::value && + std::is_convertible::value && + std::is_same().size(), *std::declval().data())>, + DataType>::value>> +bool operator<=(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + return !(other < one); +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename DataType = typename T::value_type, + typename = std::enable_if_t< + !gsl::details::is_span::value && !gsl::details::is_basic_string_span::value && + std::is_convertible::value && + std::is_same().size(), *std::declval().data())>, + DataType>::value>> +bool operator<=(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + return !(other < one); +} +#endif + +// operator> +template , Extent>>::value>> +bool operator>(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + return other < one; +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename = std::enable_if_t< + std::is_convertible, Extent>>::value && + !gsl::details::is_basic_string_span::value>> +bool operator>(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + return other < one; +} + +#ifndef _MSC_VER + +// VS treats temp and const containers as convertible to basic_string_span, +// so the cases below are already covered by the previous operators + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename DataType = typename T::value_type, + typename = std::enable_if_t< + !gsl::details::is_span::value && !gsl::details::is_basic_string_span::value && + std::is_convertible::value && + std::is_same().size(), *std::declval().data())>, + DataType>::value>> +bool operator>(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + return other < one; +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename DataType = typename T::value_type, + typename = std::enable_if_t< + !gsl::details::is_span::value && !gsl::details::is_basic_string_span::value && + std::is_convertible::value && + std::is_same().size(), *std::declval().data())>, + DataType>::value>> +bool operator>(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + return other < one; +} +#endif + +// operator >= +template , Extent>>::value>> +bool operator>=(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + return !(one < other); +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename = std::enable_if_t< + std::is_convertible, Extent>>::value && + !gsl::details::is_basic_string_span::value>> +bool operator>=(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + return !(one < other); +} + +#ifndef _MSC_VER + +// VS treats temp and const containers as convertible to basic_string_span, +// so the cases below are already covered by the previous operators + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename DataType = typename T::value_type, + typename = std::enable_if_t< + !gsl::details::is_span::value && !gsl::details::is_basic_string_span::value && + std::is_convertible::value && + std::is_same().size(), *std::declval().data())>, + DataType>::value>> +bool operator>=(gsl::basic_string_span one, const T& other) GSL_NOEXCEPT +{ + return !(one < other); +} + +template < + typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T, + typename DataType = typename T::value_type, + typename = std::enable_if_t< + !gsl::details::is_span::value && !gsl::details::is_basic_string_span::value && + std::is_convertible::value && + std::is_same().size(), *std::declval().data())>, + DataType>::value>> +bool operator>=(const T& one, gsl::basic_string_span other) GSL_NOEXCEPT +{ + return !(one < other); +} +#endif +} // namespace gsl + +#undef GSL_NOEXCEPT + +#ifdef _MSC_VER +#pragma warning(pop) + +#if _MSC_VER < 1910 +#undef constexpr +#pragma pop_macro("constexpr") + +#endif // _MSC_VER < 1910 +#endif // _MSC_VER + +#endif // GSL_STRING_SPAN_H