Function is_string

Source/external/json.hpp:20536–20539

@brief return whether value is a string @sa https://json.nlohmann.me/api/basic_json/is_string/

	/// @brief return whether value is a string
	/// @sa https://json.nlohmann.me/api/basic_json/is_string/
	constexpr bool is_string() const noexcept
	{
		return m_type == value_t::string;
	}

	/// @brief return whether value is a binary array
	/// @sa https://json.nlohmann.me/api/basic_json/is_binary/