Build on Windows using Visual Studio and export symbols from DLL

CMakeLists.txt

@@ -33,10 +33,13 @@ target_compile_features(json-schema-validator
         cxx_range_for) # for C++11 - flags
 target_compile_options(json-schema-validator
     PUBLIC
-        -Wall -Wextra) # bad, better use something else based on compiler type
+        -Wall) # bad, better use something else based on compiler type
 target_link_libraries(json-schema-validator
     PUBLIC
         json-hpp)
+target_compile_definitions(json-schema-validator
+    PRIVATE
+        -DJSON_SCHEMA_VALIDATOR_EXPORTS)
 
 # regex with boost if gcc < 4.8 - default is std::regex
 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
@@ -113,5 +116,3 @@ else()
     message(STATUS "Consider setting JSON_SCHEMA_TEST_SUITE_PATH to a path in which JSON-Schema-Test-Suite is located (github.com/json-schema-org/JSON-Schema-Test-Suite).")
 endif()
 
-
-

src/json-schema.hpp

@@ -26,6 +26,16 @@
 #ifndef NLOHMANN_JSON_SCHEMA_HPP__
 #define NLOHMANN_JSON_SCHEMA_HPP__
 
+#ifdef _WIN32
+#    ifdef JSON_SCHEMA_VALIDATOR_EXPORTS
+#        define JSON_SCHEMA_VALIDATOR_API __declspec(dllexport)
+#    else
+#        define JSON_SCHEMA_VALIDATOR_API __declspec(dllimport)
+#    endif
+#else
+#    define JSON_SCHEMA_VALIDATOR_API
+#endif
+
 #include <json.hpp>
 
 // make yourself a home - welcome to nlohmann's namespace
@@ -83,7 +93,7 @@ public:
 //
 // This is done implement the requirements described in section 8.2.
 //
-class json_uri
+class JSON_SCHEMA_VALIDATOR_API json_uri
 {
 	std::string urn_;
 
@@ -155,7 +165,7 @@ namespace json_schema_draft4
 
 extern json draft4_schema_builtin;
 
-class json_validator
+class JSON_SCHEMA_VALIDATOR_API json_validator
 {
 	std::vector<std::shared_ptr<json>> schema_store_;
 	std::shared_ptr<json> root_schema_;