tomlplusplus/include/toml++/toml_common.h
Mark Gillard abdd4f9993 added proper non-exhaustive visitor support to node::visit
also:
- fixed preprocessor snafu
- fixed bool `print_to_stream` overload not being selected
- added `TOML_SMALL_FLOAT_TYPE`
- added is_XXXXX node type metafunctions
- added additional API documentation
2020-01-19 21:49:05 +02:00

744 lines
22 KiB
C++

#pragma once
////////// CONFIGURATION
// clang-format off
#ifdef TOML_CONFIG_HEADER
#include TOML_CONFIG_HEADER
#undef TOML_CONFIG_HEADER
#endif
#ifndef TOML_CHAR_8_STRINGS
#define TOML_CHAR_8_STRINGS 0
#endif
#ifndef TOML_UNRELEASED_FEATURES
#define TOML_UNRELEASED_FEATURES 1
#endif
#ifndef TOML_LARGE_FILES
#define TOML_LARGE_FILES 0
#endif
#ifndef TOML_ASSERT
#ifdef assert
#define TOML_ASSERT(expr) assert(expr)
#else
#define TOML_ASSERT(expr) (void)0
#endif
#endif
#ifndef TOML_UNDEF_MACROS
#define TOML_UNDEF_MACROS 1
#endif
////////// COMPILER & ENVIRONMENT STUFF
#ifndef __cplusplus
#error toml++ is a C++ library.
#endif
#if defined(__clang__) || defined(__GNUC__)
#define TOML_GCC_ATTR(attr) __attribute__((attr))
#else
#define TOML_GCC_ATTR(attr)
#endif
#ifdef __clang__
#ifndef __cpp_exceptions
#define TOML_EXCEPTIONS 0
#endif
#define TOML_PUSH_WARNINGS _Pragma("clang diagnostic push")
#define TOML_DISABLE_SWITCH_WARNINGS _Pragma("clang diagnostic ignored \"-Wswitch\"")
#define TOML_DISABLE_INIT_WARNINGS _Pragma("clang diagnostic ignored \"-Wmissing-field-initializers\"")
#define TOML_DISABLE_ALL_WARNINGS _Pragma("clang diagnostic ignored \"-Weverything\"")
#define TOML_POP_WARNINGS _Pragma("clang diagnostic pop")
#define TOML_ALWAYS_INLINE TOML_GCC_ATTR(__always_inline__) inline
#define TOML_ASSUME(cond) __builtin_assume(cond)
#define TOML_UNREACHABLE __builtin_unreachable()
#if __has_declspec_attribute(novtable)
#define TOML_INTERFACE __declspec(novtable)
#endif
#if __has_declspec_attribute(empty_bases)
#define TOML_EMPTY_BASES __declspec(empty_bases)
#endif
//floating-point from_chars and to_chars are not implemented in any version of clang as of 1/1/2020
#ifndef TOML_USE_STREAMS_FOR_FLOATS
#define TOML_USE_STREAMS_FOR_FLOATS 1
#endif
#elif defined(_MSC_VER)
#ifndef _CPPUNWIND
#define TOML_EXCEPTIONS 0
#endif
#define TOML_CPP_VERSION _MSVC_LANG
#define TOML_PUSH_WARNINGS __pragma(warning(push))
#define TOML_DISABLE_SWITCH_WARNINGS __pragma(warning(disable: 4063))
#define TOML_DISABLE_ALL_WARNINGS __pragma(warning(pop)) \
__pragma(warning(push, 0))
#define TOML_POP_WARNINGS __pragma(warning(pop))
#define TOML_ALWAYS_INLINE __forceinline
#define TOML_ASSUME(cond) __assume(cond)
#define TOML_UNREACHABLE __assume(0)
#define TOML_INTERFACE __declspec(novtable)
#define TOML_EMPTY_BASES __declspec(empty_bases)
#elif defined(__GNUC__)
#ifndef __cpp_exceptions
#define TOML_EXCEPTIONS 0
#endif
#define TOML_PUSH_WARNINGS _Pragma("GCC diagnostic push")
#define TOML_DISABLE_SWITCH_WARNINGS _Pragma("GCC diagnostic ignored \"-Wswitch\"")
#define TOML_DISABLE_INIT_WARNINGS _Pragma("GCC diagnostic ignored \"-Wmissing-field-initializers\"") \
_Pragma("GCC diagnostic ignored \"-Wmaybe-uninitialized\"") \
_Pragma("GCC diagnostic ignored \"-Wuninitialized\"")
#define TOML_DISABLE_ALL_WARNINGS _Pragma("GCC diagnostic ignored \"-Wall\"") \
_Pragma("GCC diagnostic ignored \"-Wextra\"") \
_Pragma("GCC diagnostic ignored \"-Wchar-subscripts\"") \
_Pragma("GCC diagnostic ignored \"-Wtype-limits\"")
#define TOML_POP_WARNINGS _Pragma("GCC diagnostic pop")
#define TOML_ALWAYS_INLINE TOML_GCC_ATTR(__always_inline__) inline
#define TOML_UNREACHABLE __builtin_unreachable()
//floating-point from_chars and to_chars are not implemented in any version of gcc as of 1/1/2020
#ifndef TOML_USE_STREAMS_FOR_FLOATS
#define TOML_USE_STREAMS_FOR_FLOATS 1
#endif
#endif
#ifndef TOML_CPP_VERSION
#define TOML_CPP_VERSION __cplusplus
#endif
#if TOML_CPP_VERSION < 201103L
#error toml++ requires C++17 or higher. For a TOML parser supporting pre-C++11 see https://github.com/ToruNiina/Boost.toml
#elif TOML_CPP_VERSION < 201703L
#error toml++ requires C++17 or higher. For a TOML parser supporting C++11 see https://github.com/skystrife/cpptoml
#elif TOML_CPP_VERSION >= 202600L
#define TOML_CPP 26
#elif TOML_CPP_VERSION >= 202300L
#define TOML_CPP 23
#elif TOML_CPP_VERSION >= 202000L
#define TOML_CPP 20
#elif TOML_CPP_VERSION >= 201703L
#define TOML_CPP 17
#endif
#ifndef TOML_EXCEPTIONS
#define TOML_EXCEPTIONS 1
#endif
#ifndef TOML_DOXYGEN
#define TOML_DOXYGEN 0
#endif
#if TOML_EXCEPTIONS
#define TOML_CONDITIONAL_NOEXCEPT(...) noexcept(__VA_ARGS__)
#define TOML_MAY_THROW
#else
#define TOML_CONDITIONAL_NOEXCEPT(...) noexcept
#define TOML_MAY_THROW noexcept
#endif
#ifndef TOML_DISABLE_INIT_WARNINGS
#define TOML_DISABLE_INIT_WARNINGS
#endif
#ifndef TOML_USE_STREAMS_FOR_FLOATS
#define TOML_USE_STREAMS_FOR_FLOATS 0
#endif
#ifndef TOML_PUSH_WARNINGS
#define TOML_PUSH_WARNINGS
#endif
#ifndef TOML_DISABLE_ALL_WARNINGS
#define TOML_DISABLE_ALL_WARNINGS
#endif
#ifndef TOML_POP_WARNINGS
#define TOML_POP_WARNINGS
#endif
#ifndef TOML_INTERFACE
#define TOML_INTERFACE
#endif
#ifndef TOML_EMPTY_BASES
#define TOML_EMPTY_BASES
#endif
#ifndef TOML_ALWAYS_INLINE
#define TOML_ALWAYS_INLINE inline
#endif
#ifndef TOML_ASSUME
#define TOML_ASSUME(cond) (void)0
#endif
#ifndef TOML_UNREACHABLE
#define TOML_UNREACHABLE TOML_ASSERT(false)
#endif
#define TOML_NO_DEFAULT_CASE default: TOML_UNREACHABLE
#ifdef __cpp_consteval
#define TOML_CONSTEVAL consteval
#else
#define TOML_CONSTEVAL constexpr
#endif
#ifndef __INTELLISENSE__
#if __has_cpp_attribute(likely)
#define TOML_LIKELY [[likely]]
#endif
#if __has_cpp_attribute(unlikely)
#define TOML_UNLIKELY [[unlikely]]
#endif
#if __has_cpp_attribute(no_unique_address)
#define TOML_NO_UNIQUE_ADDRESS [[no_unique_address]]
#endif
#if __has_cpp_attribute(nodiscard) >= 201907L
#define TOML_NODISCARD_CTOR [[nodiscard]]
#endif
#endif //__INTELLISENSE__
#ifndef TOML_LIKELY
#define TOML_LIKELY
#endif
#ifndef TOML_UNLIKELY
#define TOML_UNLIKELY
#endif
#ifndef TOML_NO_UNIQUE_ADDRESS
#define TOML_NO_UNIQUE_ADDRESS
#endif
#ifndef TOML_NODISCARD_CTOR
#define TOML_NODISCARD_CTOR
#endif
#include "toml_version.h"
#define TOML_MAKE_VERSION(maj, min, rev) \
((maj) * 1000 + (min) * 25 + (rev))
#if TOML_UNRELEASED_FEATURES
#define TOML_LANG_EFFECTIVE_VERSION \
TOML_MAKE_VERSION(TOML_LANG_MAJOR, TOML_LANG_MINOR, TOML_LANG_REVISION+1)
#else
#define TOML_LANG_EFFECTIVE_VERSION \
TOML_MAKE_VERSION(TOML_LANG_MAJOR, TOML_LANG_MINOR, TOML_LANG_REVISION)
#endif
#define TOML_LANG_HIGHER_THAN(maj, min, rev) \
(TOML_LANG_EFFECTIVE_VERSION > TOML_MAKE_VERSION(maj, min, rev))
#define TOML_LANG_AT_LEAST(maj, min, rev) \
(TOML_LANG_EFFECTIVE_VERSION >= TOML_MAKE_VERSION(maj, min, rev))
#define TOML_LANG_EXACTLY(maj, min, rev) \
(TOML_LANG_EFFECTIVE_VERSION == TOML_MAKE_VERSION(maj, min, rev))
////////// INCLUDES
TOML_PUSH_WARNINGS
TOML_DISABLE_ALL_WARNINGS
#include <cstdint>
#include <cstring> //memcpy, memset
#include <cmath> //log10
#include <optional>
#include <memory>
#include <string_view>
#include <string>
#include <vector>
#include <map>
#include <iosfwd>
#include <charconv>
#if TOML_USE_STREAMS_FOR_FLOATS
#include <sstream>
#endif
#if TOML_EXCEPTIONS
#include <stdexcept>
#endif
TOML_POP_WARNINGS
#if TOML_CHAR_8_STRINGS
#if !defined(__cpp_lib_char8_t)
#error toml++ requires implementation support to use char8_t strings, but yours does not provide it.
#endif
#define TOML_STRING_PREFIX_1(S) u8##S
#define TOML_STRING_PREFIX(S) TOML_STRING_PREFIX_1(S)
#else
#define TOML_STRING_PREFIX(S) S
#endif
////////// FORWARD DECLARATIONS & TYPEDEFS
// clang-format on
/// \brief The root namespace for all toml++ functions and types.
namespace toml
{
inline namespace literals
{
using namespace std::string_literals;
using namespace std::string_view_literals;
[[nodiscard]] TOML_ALWAYS_INLINE
TOML_CONSTEVAL uint8_t operator"" _u8(unsigned long long n) noexcept
{
return static_cast<uint8_t>(n);
}
[[nodiscard]] TOML_ALWAYS_INLINE
TOML_CONSTEVAL size_t operator"" _sz(unsigned long long n) noexcept
{
return static_cast<size_t>(n);
}
}
#if TOML_CHAR_8_STRINGS
using string_char = char8_t;
using string = std::u8string;
using string_view = std::u8string_view;
#else
/// \brief The base character type for keys and string values.
/// \attention This will be `char8_t` if `TOML_CHAR_8_STRINGS` is `1`.
using string_char = char;
/// \brief The string type for keys and string values.
/// \attention This will be `std::u8string` if `TOML_CHAR_8_STRINGS` is `1`.
using string = std::string;
/// \brief The string type for keys and string values.
/// \attention This will be `std::u8string_view` if `TOML_CHAR_8_STRINGS` is `1`.
using string_view = std::string_view;
#endif
struct date;
struct time;
struct time_offset;
struct date_time;
class node;
template <typename T> class node_view;
template <typename T> class value;
class array;
class table;
/// \brief TOML node type identifiers.
enum class node_type : uint8_t
{
table,
array,
string,
integer,
floating_point,
boolean,
date,
time,
date_time
};
#if TOML_LARGE_FILES
using source_index = uint32_t;
#else
/// \brief The integer type used to tally line numbers and columns.
/// \attention This will be `uint32_t` if `TOML_LARGE_FILES` is `1`.
using source_index = uint16_t;
#endif
/// \brief A source document line-and-column pair.
struct source_position
{
/// \brief The line number.
/// \remarks Valid line numbers start at 1.
source_index line;
/// \brief The column number.
/// \remarks Valid column numbers start at 1.
source_index column;
/// \brief Returns true if both line and column numbers are non-zero.
[[nodiscard]]
explicit constexpr operator bool () const noexcept
{
return line > source_index{} && column > source_index{};
}
[[nodiscard]]
friend constexpr bool operator == (const source_position& lhs, const source_position& rhs) noexcept
{
return lhs.line == rhs.line
&& lhs.column == rhs.column;
}
[[nodiscard]]
friend constexpr bool operator != (const source_position& lhs, const source_position& rhs) noexcept
{
return lhs.line != rhs.line
|| lhs.column != rhs.column;
}
[[nodiscard]]
friend constexpr bool operator < (const source_position& lhs, const source_position& rhs) noexcept
{
return lhs.line < rhs.line
|| (lhs.line == rhs.line && lhs.column < rhs.column);
}
[[nodiscard]]
friend constexpr bool operator <= (const source_position& lhs, const source_position& rhs) noexcept
{
return lhs.line < rhs.line
|| (lhs.line == rhs.line && lhs.column <= rhs.column);
}
template <typename CHAR>
friend std::basic_ostream<CHAR>& operator << (std::basic_ostream<CHAR>& lhs, const source_position& rhs)
TOML_MAY_THROW
{
return lhs << "line " << rhs.line << ", column " << rhs.column;
}
};
/// \brief A pointer to a shared string resource containing a source path.
using source_path_ptr = std::shared_ptr<const std::string>;
/// \brief A source document region.
struct source_region
{
/// \brief The beginning of the region (inclusive).
source_position begin;
/// \brief The end of the region (exclusive).
source_position end;
/// \brief The path to the corresponding source document.
///
/// \remarks This will be `nullptr` if no path was provided to toml::parse().
source_path_ptr path;
};
TOML_PUSH_WARNINGS
TOML_DISABLE_INIT_WARNINGS
#if TOML_DOXYGEN || !TOML_EXCEPTIONS
/// \brief An error thrown/returned when parsing fails.
///
/// \remarks This class inherits from `std::runtime_error` when exceptions are enabled.
/// The public interface is the same regardless of exception mode.
class parse_error final
{
private:
std::string description_;
source_region source_;
public:
TOML_NODISCARD_CTOR
parse_error(std::string&& desc, source_region&& src) noexcept
: description_{ std::move(desc) },
source_{ std::move(src) }
{}
TOML_NODISCARD_CTOR
parse_error(std::string&& desc, const source_region& src) noexcept
: parse_error{ std::move(desc), source_region{ src } }
{}
TOML_NODISCARD_CTOR
parse_error(std::string&& desc, const source_position& position, const source_path_ptr& path = {}) noexcept
: parse_error{ std::move(desc), source_region{ position, position, path } }
{}
/// \brief Returns a textual description of the error.
[[nodiscard]]
std::string_view description() const noexcept
{
return description_;
}
/// \brief Returns the region of the source document responsible for the error.
[[nodiscard]]
const source_region& source() const noexcept
{
return source_;
}
};
#else
class parse_error final
: public std::runtime_error
{
private:
source_region source_;
public:
TOML_NODISCARD_CTOR TOML_GCC_ATTR(nonnull)
parse_error(const char* desc, source_region&& src) noexcept
: std::runtime_error{ desc },
source_{ std::move(src) }
{}
TOML_NODISCARD_CTOR TOML_GCC_ATTR(nonnull)
parse_error(const char* desc, const source_region& src) noexcept
: parse_error{ desc, source_region{ src } }
{}
TOML_NODISCARD_CTOR TOML_GCC_ATTR(nonnull)
parse_error(const char* desc, const source_position& position, const source_path_ptr& path = {}) noexcept
: parse_error{ desc, source_region{ position, position, path } }
{}
[[nodiscard]]
std::string_view description() const noexcept
{
return std::string_view{ what() };
}
[[nodiscard]]
const source_region& source() const noexcept
{
return source_;
}
};
#endif
TOML_POP_WARNINGS
}
/// \brief Internal implementation details. No user-serviceable parts within.
namespace toml::impl
{
template <typename T>
using string_map = std::map<string, T, std::less<>>; //heterogeneous lookup
#if defined(__cpp_lib_remove_cvref) || (defined(_MSC_VER) && defined(_HAS_CXX20))
template <typename T>
using remove_cvref_t = std::remove_cvref_t<T>;
#else
template <typename T>
using remove_cvref_t = std::remove_cv_t<std::remove_reference_t<T>>;
#endif
template <typename T>
[[nodiscard]] TOML_ALWAYS_INLINE
constexpr std::underlying_type_t<T> unwrap_enum(T val) noexcept
{
return static_cast<std::underlying_type_t<T>>(val);
}
// Q: "why not use std::find??"
// A: Because <algorithm> is _huge_ and std::find would be the only thing I used from it.
// I don't want to impose such a heavy burden on users.
template <typename T>
inline std::optional<size_t> find(const std::vector<T>& haystack, const T& needle) noexcept
{
const auto end = haystack.size();
for (size_t i = 0; i < end; i++)
if (haystack[i] == needle)
return i;
return {};
}
class parser;
template <typename T>
inline constexpr bool is_value =
std::is_same_v<T, string>
|| std::is_same_v<T, int64_t>
|| std::is_same_v<T, double>
|| std::is_same_v<T, bool>
|| std::is_same_v<T, date>
|| std::is_same_v<T, time>
|| std::is_same_v<T, date_time>;
template <typename T>
inline constexpr bool is_value_or_promotable =
is_value<T>
|| std::is_same_v<T, string_view>
|| std::is_same_v<T, int32_t>
|| std::is_same_v<T, int16_t>
|| std::is_same_v<T, int8_t>
|| std::is_same_v<T, uint32_t>
|| std::is_same_v<T, uint16_t>
|| std::is_same_v<T, uint8_t>
|| std::is_same_v<T, float>
#ifdef TOML_SMALL_FLOAT_TYPE
|| std::is_same_v<T, TOML_SMALL_FLOAT_TYPE>
#endif
;
template <typename T>
inline constexpr bool is_value_or_node =
is_value<T>
|| std::is_same_v<T, array>
|| std::is_same_v<T, table>;
template <typename T> struct node_wrapper { using type = T; };
template <> struct node_wrapper<string> { using type = value<string>; };
template <> struct node_wrapper<int64_t> { using type = value<int64_t>; };
template <> struct node_wrapper<double> { using type = value<double>; };
template <> struct node_wrapper<bool> { using type = value<bool>; };
template <> struct node_wrapper<date> { using type = value<date>; };
template <> struct node_wrapper<time> { using type = value<time>; };
template <> struct node_wrapper<date_time> { using type = value<date_time>; };
template <typename T> struct node_unwrapper { using type = T; };
template <typename T> struct node_unwrapper<value<T>> { using type = T; };
template <typename T> struct value_promoter { using type = T; };
template <> struct value_promoter<string_view> { using type = string; };
template <> struct value_promoter<int32_t> { using type = int64_t; };
template <> struct value_promoter<int16_t> { using type = int64_t; };
template <> struct value_promoter<int8_t> { using type = int64_t; };
template <> struct value_promoter<uint32_t> { using type = int64_t; };
template <> struct value_promoter<uint16_t> { using type = int64_t; };
template <> struct value_promoter<uint8_t> { using type = int64_t; };
template <> struct value_promoter<float> { using type = double; };
#ifdef TOML_SMALL_FLOAT_TYPE
template <> struct value_promoter<TOML_SMALL_FLOAT_TYPE> { using type = double; };
#endif
template <typename T> using promoted = typename impl::value_promoter<T>::type;
inline constexpr toml::string_view low_character_escape_table[] =
{
TOML_STRING_PREFIX("\\u0000"sv),
TOML_STRING_PREFIX("\\u0001"sv),
TOML_STRING_PREFIX("\\u0002"sv),
TOML_STRING_PREFIX("\\u0003"sv),
TOML_STRING_PREFIX("\\u0004"sv),
TOML_STRING_PREFIX("\\u0005"sv),
TOML_STRING_PREFIX("\\u0006"sv),
TOML_STRING_PREFIX("\\u0007"sv),
TOML_STRING_PREFIX("\\b"sv),
TOML_STRING_PREFIX("\\t"sv),
TOML_STRING_PREFIX("\\n"sv),
TOML_STRING_PREFIX("\\u000B"sv),
TOML_STRING_PREFIX("\\f"sv),
TOML_STRING_PREFIX("\\r"sv),
TOML_STRING_PREFIX("\\u000E"sv),
TOML_STRING_PREFIX("\\u000F"sv),
TOML_STRING_PREFIX("\\u0010"sv),
TOML_STRING_PREFIX("\\u0011"sv),
TOML_STRING_PREFIX("\\u0012"sv),
TOML_STRING_PREFIX("\\u0013"sv),
TOML_STRING_PREFIX("\\u0014"sv),
TOML_STRING_PREFIX("\\u0015"sv),
TOML_STRING_PREFIX("\\u0016"sv),
TOML_STRING_PREFIX("\\u0017"sv),
TOML_STRING_PREFIX("\\u0018"sv),
TOML_STRING_PREFIX("\\u0019"sv),
TOML_STRING_PREFIX("\\u001A"sv),
TOML_STRING_PREFIX("\\u001B"sv),
TOML_STRING_PREFIX("\\u001C"sv),
TOML_STRING_PREFIX("\\u001D"sv),
TOML_STRING_PREFIX("\\u001E"sv),
TOML_STRING_PREFIX("\\u001F"sv),
};
inline constexpr std::string_view node_type_friendly_names[] =
{
"table"sv,
"array"sv,
"string"sv,
"integer"sv,
"floating-point"sv,
"boolean"sv,
"date"sv,
"time"sv,
"date-time"sv
};
#define TOML_P2S_DECL(linkage, type) \
template <typename CHAR> \
linkage void print_to_stream(type, std::basic_ostream<CHAR>&) TOML_MAY_THROW
TOML_P2S_DECL(TOML_ALWAYS_INLINE, int8_t);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, int16_t);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, int32_t);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, int64_t);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, uint8_t);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, uint16_t);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, uint32_t);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, uint64_t);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, float);
TOML_P2S_DECL(TOML_ALWAYS_INLINE, double);
TOML_P2S_DECL(inline, const date&);
TOML_P2S_DECL(inline, const time&);
TOML_P2S_DECL(inline, time_offset);
TOML_P2S_DECL(inline, const date_time&);
#undef TOML_P2S_DECL
}
namespace toml
{
/// \brief Helper alias that wraps a type up as it's TOML node equivalent.
template <typename T>
using node_of = typename impl::node_wrapper<T>::type;
/// \brief Helper alias that unwraps TOML node type to it's raw value equivalent.
template <typename T>
using value_of = typename impl::node_unwrapper<T>::type;
/// \brief Metafunction for determining if a type is a toml::table.
template <typename T>
inline constexpr bool is_table = std::is_same_v<impl::remove_cvref_t<T>, table>;
/// \brief Metafunction for determining if a type is a toml::array.
template <typename T>
inline constexpr bool is_array = std::is_same_v<impl::remove_cvref_t<T>, array>;
/// \brief Metafunction for determining if a type is a toml::value<string>.
template <typename T>
inline constexpr bool is_string = std::is_same_v<node_of<impl::remove_cvref_t<T>>, value<string>>;
/// \brief Metafunction for determining if a type is a toml::value<int64_t>.
template <typename T>
inline constexpr bool is_integer = std::is_same_v<node_of<impl::remove_cvref_t<T>>, value<int64_t>>;
/// \brief Metafunction for determining if a type is a toml::value<double>.
template <typename T>
inline constexpr bool is_floating_point = std::is_same_v<node_of<impl::remove_cvref_t<T>>, value<double>>;
/// \brief Metafunction for determining if a type is a toml::value<bool>.
template <typename T>
inline constexpr bool is_boolean = std::is_same_v<node_of<impl::remove_cvref_t<T>>, value<bool>>;
/// \brief Metafunction for determining if a type is a toml::value<toml::date>.
template <typename T>
inline constexpr bool is_date = std::is_same_v<node_of<impl::remove_cvref_t<T>>, value<date>>;
/// \brief Metafunction for determining if a type is a toml::value<toml::time>.
template <typename T>
inline constexpr bool is_time = std::is_same_v<node_of<impl::remove_cvref_t<T>>, value<time>>;
/// \brief Metafunction for determining if a type is a toml::value<toml::date_time>.
template <typename T>
inline constexpr bool is_date_time = std::is_same_v<node_of<impl::remove_cvref_t<T>>, value<date_time>>;
/// \brief Pretty-prints the value of a node_type to a stream.
template <typename CHAR>
inline std::basic_ostream<CHAR>& operator << (std::basic_ostream<CHAR>& lhs, node_type rhs) TOML_MAY_THROW
{
using underlying_t = std::underlying_type_t<node_type>;
if constexpr (std::is_same_v<CHAR, char>)
return lhs << impl::node_type_friendly_names[static_cast<underlying_t>(rhs)];
else if constexpr (sizeof(CHAR) == 1)
{
const auto str = impl::node_type_friendly_names[static_cast<underlying_t>(rhs)];
return lhs << std::basic_string_view<CHAR>{ reinterpret_cast<const CHAR*>(str.data()), str.length() };
}
else
return lhs << lhs.data();
}
}