5352856f04
* Add key_compare member to ordered_map
* Replace == with key_compare in ordered_map
* Expose the actual comparison function used by object_t
nlohmann::ordered_map uses a different comparison function than the one
provided via template parameter.
* Introduce a type trait to detect if object_t has a key_compare member.
* Rename object_comparator_t to default_object_comparator_t.
* Add object_comparator_t to be conditionally defined as
object_t::key_compare, if available, or default_object_comparator_t
otherwise.
* Update the documentation accordingly.
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
* Add type traits to check if a type is usable as object key
Add type trait to check:
* if a type is a specialization of a template.
* if a type is a json_pointer.
* if a type is a basic_json::{const_,}iterator.
* if two types are comparable using a given comparison functor.
* if a type is comparable to basic_json::object_t::key_type.
* if a type has a member type is_transparent.
* if a type is usable as object key.
* if a type has an erase() function accepting a given KeyType.
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
* Rework basic_json element access to accept more key types
Rework basic_json element access member functions and operators to
accept any type that meets the requirements defined by type trait
detail::is_usable_as_key_type.
Member functions and operators:
* at()
* operator[]
* value()
* erase()
* find()
* count()
* contains()
Update documentation to reflect these changes.
Add unit tests to excercise the new functions using std::string_view.
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
180 lines
6.4 KiB
Markdown
180 lines
6.4 KiB
Markdown
# <small>nlohmann::basic_json::</small>insert
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```cpp
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// (1)
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iterator insert(const_iterator pos, const basic_json& val);
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iterator insert(const_iterator pos, basic_json&& val);
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// (2)
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iterator insert(const_iterator pos, size_type cnt, const basic_json& val);
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// (3)
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iterator insert(const_iterator pos, const_iterator first, const_iterator last);
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// (4)
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iterator insert(const_iterator pos, initializer_list_t ilist);
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// (5)
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void insert(const_iterator first, const_iterator last);
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```
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1. Inserts element `val` into array before iterator `pos`.
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2. Inserts `cnt` copies of `val` into array before iterator `pos`.
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3. Inserts elements from range `[first, last)` into array before iterator `pos`.
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4. Inserts elements from initializer list `ilist` into array before iterator `pos`.
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5. Inserts elements from range `[first, last)` into object.
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## Parameters
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`pos` (in)
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: iterator before which the content will be inserted; may be the `end()` iterator
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`val` (in)
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: value to insert
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`cnt` (in)
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: number of copies of `val` to insert
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`first` (in)
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: begin of the range of elements to insert
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`last` (in)
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: end of the range of elements to insert
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`ilist` (in)
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: initializer list to insert the values from
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## Return value
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1. iterator pointing to the inserted `val`.
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2. iterator pointing to the first element inserted, or `pos` if `#!cpp cnt==0`
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3. iterator pointing to the first element inserted, or `pos` if `#!cpp first==last`
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4. iterator pointing to the first element inserted, or `pos` if `ilist` is empty
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5. (none)
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## Exception safety
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Strong exception safety: if an exception occurs, the original value stays intact.
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## Exceptions
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1. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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arrays; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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2. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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arrays; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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3. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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arrays; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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- Throws [`invalid_iterator.210`](../../home/exceptions.md#jsonexceptioninvalid_iterator210) if `first` and `last`
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do not belong to the same JSON value; example: `"iterators do not fit"`
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- Throws [`invalid_iterator.211`](../../home/exceptions.md#jsonexceptioninvalid_iterator211) if `first` or `last`
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are iterators into container for which insert is called; example: `"passed iterators may not belong to container"`
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4. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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arrays; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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5. The function can throw the following exceptions:
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- Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if called on JSON values other than
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objects; example: `"cannot use insert() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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- Throws [`invalid_iterator.210`](../../home/exceptions.md#jsonexceptioninvalid_iterator210) if `first` and `last`
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do not belong to the same JSON value; example: `"iterators do not fit"`
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## Complexity
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1. Constant plus linear in the distance between `pos` and end of the container.
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2. Linear in `cnt` plus linear in the distance between `pos` and end of the container.
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3. Linear in `#!cpp std::distance(first, last)` plus linear in the distance between `pos` and end of the container.
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4. Linear in `ilist.size()` plus linear in the distance between `pos` and end of the container.
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5. Logarithmic: `O(N*log(size() + N))`, where `N` is the number of elements to insert.
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## Examples
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??? example "Example (1): insert element into array"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert.output"
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```
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??? example "Example (2): insert copies of element into array"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert__count.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert__count.output"
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```
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??? example "Example (3): insert range of elements into array"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert__range.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert__range.output"
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```
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??? example "Example (4): insert elements from initializer list into array"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert__ilist.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert__ilist.output"
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```
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??? example "Example (5): insert range of elements into object"
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The example shows how `insert()` is used.
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```cpp
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--8<-- "examples/insert__range_object.cpp"
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```
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Output:
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```json
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--8<-- "examples/insert__range_object.output"
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```
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## Version history
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1. Added in version 1.0.0.
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2. Added in version 1.0.0.
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3. Added in version 1.0.0.
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4. Added in version 1.0.0.
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5. Added in version 3.0.0.
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