feat: update codes to v4

include/toml_fwd.hpp

@@ -0,0 +1,89 @@
+#ifndef TOML11_TOML_FWD_HPP
+#define TOML11_TOML_FWD_HPP
+
+// IWYU pragma: begin_exports
+#include "toml11/version.hpp"
+#include "toml11/compat.hpp"
+#include "toml11/conversion.hpp"
+#include "toml11/from.hpp"
+#include "toml11/into.hpp"
+// IWYU pragma: end_exports
+
+#include <cstdint>
+
+#ifdef TOML11_COLORIZE_ERROR_MESSAGE
+#define TOML11_ERROR_MESSAGE_COLORIZED true
+#else
+#define TOML11_ERROR_MESSAGE_COLORIZED false
+#endif
+
+namespace toml
+{
+class discard_comments;
+class preserve_comments;
+
+enum class month_t : std::uint8_t;
+struct local_date;
+struct local_time;
+struct time_offset;
+struct local_datetime;
+struct offset_datetime;
+
+struct error_info;
+
+struct exception;
+
+enum class indent_char : std::uint8_t;
+enum class integer_format : std::uint8_t;
+enum class floating_format : std::uint8_t;
+enum class string_format : std::uint8_t;
+enum class datetime_delimiter_kind : std::uint8_t;
+enum class array_format : std::uint8_t;
+enum class table_format : std::uint8_t;
+
+struct boolean_format_info;
+struct integer_format_info;
+struct floating_format_info;
+struct string_format_info;
+struct offset_datetime_format_info;
+struct local_datetime_format_info;
+struct local_date_format_info;
+struct local_time_format_info;
+struct array_format_info;
+struct table_format_info;
+
+template<typename Key, typename Val, typename Cmp = std::equal_to<Key>,
+         typename Allocator = std::allocator<std::pair<Key, Val>>>
+class ordered_map;
+
+struct syntax_error;
+struct file_io_error;
+
+struct bad_result_access;
+template<typename T>
+struct success;
+template<typename T>
+struct failure;
+template<typename T, typename E>
+struct result;
+
+struct source_location;
+
+struct semantic_version;
+struct spec;
+
+
+template<typename TypeConfig>
+class basic_value;
+struct type_error;
+
+struct type_config;
+using value = basic_value<type_config>;
+
+struct ordered_type_config;
+using ordered_value = basic_value<ordered_type_config>;
+
+enum class value_t : std::uint8_t;
+
+} // toml
+#endif// TOML11_TOML_HPP