nameof_module/include/nameof.hpp
2019-04-08 23:02:45 +05:00

265 lines
10 KiB
C++

// _ _ __ _____
// | \ | | / _| / ____|_ _
// | \| | __ _ _ __ ___ ___ ___ | |_ | | _| |_ _| |_
// | . ` |/ _` | '_ ` _ \ / _ \/ _ \| _| | | |_ _|_ _|
// | |\ | (_| | | | | | | __/ (_) | | | |____|_| |_|
// |_| \_|\__,_|_| |_| |_|\___|\___/|_| \_____|
// https://github.com/Neargye/nameof
// vesion 0.7.5
//
// Licensed under the MIT License <http://opensource.org/licenses/MIT>.
// SPDX-License-Identifier: MIT
// Copyright (c) 2016, 2018 - 2019 Daniil Goncharov <neargye@gmail.com>.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#pragma once
#include <array>
#include <cstddef>
#include <limits>
#include <type_traits>
#include <string_view>
namespace nameof {
// Enum value must be in range [-256, 256]. If you need another range, add specialization enum_range for necessary enum type.
template <typename E>
struct enum_range final {
static_assert(std::is_enum_v<E>, "nameof::enum_range requires enum type.");
static constexpr int min = std::is_signed_v<std::underlying_type_t<E>> ? -256 : 0;
static constexpr int max = 256;
};
namespace detail {
template <typename T>
struct identity final {
using type = T;
};
[[nodiscard]] constexpr bool is_name_char(char c, bool front) noexcept {
return (!front && c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_';
}
[[nodiscard]] constexpr std::string_view pretty_name(std::string_view name, bool with_template_suffix) noexcept {
if (name.length() >= 1 && (name.front() == '"' || name.front() == '\'')) {
return {}; // Narrow multibyte string literal.
} else if (name.length() >= 2 && name[0] == 'R' && (name[1] == '"' || name[1] == '\'')) {
return {}; // Raw string literal.
} else if (name.length() >= 2 && name[0] == 'L' && (name[1] == '"' || name[1] == '\'')) {
return {}; // Wide string literal.
} else if (name.length() >= 2 && name[0] == 'U' && (name[1] == '"' || name[1] == '\'')) {
return {}; // UTF-32 encoded string literal.
} else if (name.length() >= 2 && name[0] == 'u' && (name[1] == '"' || name[1] == '\'')) {
return {}; // UTF-16 encoded string literal.
} else if (name.length() >= 3 && name[0] == 'u' && name[1] == '8' && (name[2] == '"' || name[2] == '\'')) {
return {}; // UTF-8 encoded string literal.
} else if (name.length() >= 1 && (name.front() >= '0' && name.front() <= '9')) {
return {}; // Invalid name.
}
for (std::size_t i = name.size(), h = 0, s = 0; i > 0; --i) {
if (name[i - 1] == ')') {
++h;
++s;
continue;
} else if (name[i - 1] == '(') {
--h;
++s;
continue;
}
if (h == 0) {
name.remove_suffix(s);
break;
} else {
++s;
continue;
}
}
std::size_t s = 0;
for (std::size_t i = name.size(), h = 0; i > 0; --i) {
if (name[i - 1] == '>') {
++h;
++s;
continue;
} else if (name[i - 1] == '<') {
--h;
++s;
continue;
}
if (h == 0) {
break;
} else {
++s;
continue;
}
}
for (std::size_t i = name.size() - s; i > 0; --i) {
if (!is_name_char(name[i - 1], false)) {
name.remove_prefix(i);
break;
}
}
name.remove_suffix(with_template_suffix ? 0 : s);
if (name.length() > 0 && is_name_char(name.front(), true)) {
return name;
} else {
return {}; // Invalid name.
}
}
template <typename T>
[[nodiscard]] constexpr std::string_view nameof_type_impl() noexcept {
#if defined(__clang__)
std::string_view name{__PRETTY_FUNCTION__};
constexpr auto prefix = sizeof("std::string_view nameof::detail::nameof_type_impl() [T = nameof::detail::identity<") - 1;
constexpr auto suffix = sizeof(">]") - 1;
#elif defined(__GNUC__)
std::string_view name{__PRETTY_FUNCTION__};
constexpr auto prefix = sizeof("constexpr std::string_view nameof::detail::nameof_type_impl() [with T = nameof::detail::identity<") - 1;
constexpr auto suffix = sizeof(">; std::string_view = std::basic_string_view<char>]") - 1;
#elif defined(_MSC_VER)
std::string_view name{__FUNCSIG__};
constexpr auto prefix = sizeof("class std::basic_string_view<char,struct std::char_traits<char> > __cdecl nameof::detail::nameof_type_impl<struct nameof::detail::identity<") - 1;
constexpr auto suffix = sizeof(">>(void) noexcept") - 1;
#else
return {}; // Unsupported compiler.
#endif
#if defined(__clang__) || defined(__GNUC__) || defined(_MSC_VER)
name.remove_prefix(prefix);
name.remove_suffix(suffix);
# if defined(_MSC_VER)
if (name.size() > sizeof("enum") && name[0] == 'e' && name[1] == 'n' && name[2] == 'u' && name[3] == 'm' && name[4] == ' ') {
name.remove_prefix(sizeof("enum"));
}
if (name.size() > sizeof("class") && name[0] == 'c' && name[1] == 'l' && name[2] == 'a' && name[3] == 's' && name[4] == 's' && name[5] == ' ') {
name.remove_prefix(sizeof("class"));
}
if (name.size() > sizeof("struct") && name[0] == 's' && name[1] == 't' && name[2] == 'r' && name[3] == 'u' && name[4] == 'c' && name[5] == 't' && name[6] == ' ') {
name.remove_prefix(sizeof("struct"));
}
# endif
while (name.back() == ' ') {
name.remove_suffix(1);
}
return name;
#endif
}
template <typename E, E V>
[[nodiscard]] constexpr std::string_view enum_name_impl() noexcept {
static_assert(std::is_enum_v<E>, "nameof::enum_name_impl requires enum type.");
#if defined(__clang__)
std::string_view name{__PRETTY_FUNCTION__};
constexpr auto suffix = sizeof("]") - 1;
#elif defined(__GNUC__) && __GNUC__ >= 9
std::string_view name{__PRETTY_FUNCTION__};
constexpr auto suffix = sizeof("; std::string_view = std::basic_string_view<char>]") - 1;
#elif defined(_MSC_VER)
std::string_view name{__FUNCSIG__};
constexpr auto suffix = sizeof(">(void) noexcept") - 1;
#else
return {}; // Unsupported compiler.
#endif
#if defined(__clang__) || (defined(__GNUC__) && __GNUC__ >= 9) || defined(_MSC_VER)
name.remove_suffix(suffix);
return pretty_name(name, false);
#endif
}
template <typename E, int... I>
[[nodiscard]] constexpr decltype(auto) enum_strings_impl(std::integer_sequence<int, I...>) noexcept {
static_assert(std::is_enum_v<E>, "magic_enum::detail::enum_strings_impl requires enum type.");
using U = std::underlying_type_t<E>;
constexpr int min = (enum_range<E>::min > std::numeric_limits<U>::min()) ? enum_range<E>::min : std::numeric_limits<U>::min();
constexpr std::array<std::string_view, sizeof...(I)> enum_names{{enum_name_impl<E, static_cast<E>(I + min)>()...}};
return enum_names;
}
template <typename E>
[[nodiscard]] constexpr std::string_view nameof_enum_impl(int value) noexcept {
static_assert(std::is_enum_v<E>, "magic_enum::detail::nameof_enum_impl requires enum type.");
using U = std::underlying_type_t<E>;
constexpr int max = (enum_range<E>::max < std::numeric_limits<U>::max()) ? enum_range<E>::max : std::numeric_limits<U>::max();
constexpr int min = (enum_range<E>::min > std::numeric_limits<U>::min()) ? enum_range<E>::min : std::numeric_limits<U>::min();
constexpr auto enum_range = std::make_integer_sequence<int, max - min + 1>{};
constexpr auto enum_names = enum_strings_impl<E>(enum_range);
const int i = value - min;
if (i >= 0 && static_cast<std::size_t>(i) < enum_names.size()) {
return enum_names[i];
} else {
return {}; // Value or out of range.
}
}
template <typename T>
[[nodiscard]] constexpr std::string_view nameof_impl(std::string_view name, bool with_template_suffix) noexcept {
return pretty_name(name, with_template_suffix);
}
template <typename T>
[[nodiscard]] constexpr std::string_view nameof_raw_impl(std::string_view name) noexcept {
return name;
}
} // namespace detail
// Obtains simple (unqualified) string enum name of enum variable.
template <typename T, typename = std::enable_if_t<std::is_enum_v<std::decay_t<T>>>>
[[nodiscard]] constexpr std::string_view nameof_enum(T value) noexcept {
return detail::nameof_enum_impl<std::decay_t<T>>(static_cast<int>(value));
}
// Obtains string name of type.
template <typename T>
[[nodiscard]] constexpr std::string_view nameof_type() noexcept {
return detail::nameof_type_impl<detail::identity<T>>();
}
} // namespace nameof
// NAMEOF obtains simple (unqualified) string name of variable, function, enum, macro.
#define NAMEOF(...) ::nameof::detail::nameof_impl<decltype(__VA_ARGS__)>(#__VA_ARGS__, false)
// Obtains simple (unqualified) full (with template suffix) string name of variable, function, enum, macro.
#define NAMEOF_FULL(...) ::nameof::detail::nameof_impl<decltype(__VA_ARGS__)>(#__VA_ARGS__, true)
// Obtains raw string name of variable, function, enum, macro.
#define NAMEOF_RAW(...) ::nameof::detail::nameof_raw_impl<decltype(__VA_ARGS__)>(#__VA_ARGS__)
// Obtains simple (unqualified) string enum name of enum variable.
#define NAMEOF_ENUM(...) ::nameof::nameof_enum<decltype(__VA_ARGS__)>(__VA_ARGS__)
// Obtains string name of type.
#define NAMEOF_TYPE(...) ::nameof::nameof_type<__VA_ARGS__>()
// Obtains string name of variable type.
#define NAMEOF_VAR_TYPE(...) ::nameof::nameof_type<decltype(__VA_ARGS__)>()