json5

json5 is a small header only C++ library for parsing JSON or JSON5 data. It also comes with a simple reflection system for easy serialization and deserialization of C++ structs.

Quick Example:

#include <json5/json5_input.hpp>
#include <json5/json5_output.hpp>

struct Settings
{
	int x = 0;
	int y = 0;
	int width = 0;
	int height = 0;
	bool fullscreen = false;
	std::string renderer = "";

	JSON5_MEMBERS(x, y, width, height, fullscreen, renderer)
};

Settings s;

// Fill 's' instance from file
json5::from_file("settings.json", s);

// Save 's' to file
json5::to_file("settings.json", s);

json5.hpp

TBD

json5_input.hpp

Provides functions to load json5::document from string, stream or file.

json5_output.hpp

Provides functions to convert json5::document into string, stream or file.

json5_builder.hpp

json5_reflect.hpp

Basic supported types:

• bool
• int, float, double
• std::string
• std::vector, std::map, std::unordered_map, std::array
• C array

json5_base.hpp

json5_filter.hpp

FAQ

TBD

Additional examples

Serialize custom type:

// Let's have a 3D vector struct:
struct vec3 { float x, y, z; };

// Let's have a triangle struct with 'vec3' members
struct Triangle
{
	vec3 a, b, c;
};

JSON5_CLASS(Triangle, a, b, c)

namespace json5::detail {

// Write vec3 as JSON array of 3 numbers
inline json5::value write( writer &w, const vec3 &in )
{
	w.push_array();
	w += write( w, in.x );
	w += write( w, in.y );
	w += write( w, in.z );
	return w.pop();
}

// Read vec3 from JSON array
inline error read( const json5::value &in, vec3 &out )
{
	return read( json5::array_view( in ), out.x, out.y, out.z );
}

} // namespace json5::detail

Serialize enum:

enum class MyEnum
{
	Zero,
	First,
	Second,
	Third
};

// (must be placed in global namespce, requires C++20)
JSON5_ENUM( MyEnum, Zero, First, Second, Third )