├── LICENSE
├── README.md
└── include
    └── EnumFlags.hpp


/LICENSE:
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 1 | MIT License
 2 | 
 3 | Copyright (c) 2022 iFarbod
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


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/README.md:
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 1 | # cpp17-enum-flag
 2 | Enable bitwise operators on scoped enums.
 3 | 
 4 | Library compiles with no warnings (`-std=c++17 -Wall -Wshadow -Wextra -Wnon-virtual-dtor -pedantic`) on Clang 14.
 5 | 
 6 | ## Example usage
 7 | 
 8 | ```cpp
 9 | enum class TestEnum
10 | {
11 |     Baz = 1 << 0,
12 |     Fou = 1 << 1,
13 |     Moo = 1 << 2,
14 |     Foo = 1 << 3,
15 |     Bar = 1 << 4,
16 | };
17 | 
18 | template <>
19 | struct zsl::EnumFlags<TestEnum>
20 | {
21 |     static constexpr bool is_flags = true;
22 | };
23 | 
24 | // ...
25 | 
26 | auto main() -> int
27 | {
28 |     TestEnum e{TestEnum::Baz};
29 |     auto b = zsl::EnumIsSet(e & TestEnum::Baz);
30 |     std::cout << (b ? "true" : "false");
31 |     
32 |     e = TestEnum::Foo | TestEnum::Baz;
33 |     return 0;
34 | }
35 | ```
36 | 


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/include/EnumFlags.hpp:
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  1 | // Copyright (c) 2018-2022 iFarbod and other contributors. All Rights Reserved.
  2 | //
  3 | // SPDX-License-Identifier: MIT
  4 | 
  5 | #pragma once
  6 | 
  7 | #include <type_traits>
  8 | 
  9 | namespace zsl
 10 | {
 11 | 
 12 | // Example usage:
 13 | // template <>
 14 | // struct zsl::EnumFlags<zg::FooEnum>
 15 | // {
 16 | //     static constexpr bool is_flags = true;
 17 | // };
 18 | 
 19 | template <typename T>
 20 | struct EnumFlags
 21 | {
 22 | };
 23 | 
 24 | template <typename T, typename = void>
 25 | struct HasIsFlags : std::false_type
 26 | {
 27 | };
 28 | 
 29 | template <typename T>
 30 | struct HasIsFlags<T, std::void_t<decltype(EnumFlags<T>::is_flags)>>
 31 |     : std::bool_constant<std::is_same_v<bool, std::decay_t<decltype(EnumFlags<T>::is_flags)>>>
 32 | {
 33 | };
 34 | 
 35 | template <typename T>
 36 | constexpr auto IsFlagsEnum() -> bool
 37 | {
 38 |     if constexpr (HasIsFlags<T>::value)
 39 |     {
 40 |         return EnumFlags<T>::is_flags;
 41 |     }
 42 |     return false;
 43 | }
 44 | 
 45 | template <typename T>
 46 | inline constexpr bool IsFlagsV = IsFlagsEnum<T>();
 47 | 
 48 | template <typename T>
 49 | constexpr auto EnumIsSet(T e) -> std::enable_if_t<std::is_enum_v<T> && zsl::IsFlagsV<T>, bool>
 50 | {
 51 |     return static_cast<bool>(e);
 52 | }
 53 | 
 54 | }  // namespace zsl
 55 | 
 56 | template <typename T, std::enable_if_t<std::is_enum_v<T> && zsl::IsFlagsV<T>, int> = 0>
 57 | constexpr auto operator&(T lhs, T rhs) -> T
 58 | {
 59 |     using UnderlyingType = std::underlying_type_t<T>;
 60 |     return static_cast<T>(static_cast<UnderlyingType>(lhs) & static_cast<UnderlyingType>(rhs));
 61 | }
 62 | 
 63 | template <typename T, std::enable_if_t<std::is_enum_v<T> && zsl::IsFlagsV<T>, int> = 0>
 64 | constexpr auto operator|(T lhs, T rhs) -> T
 65 | {
 66 |     using UnderlyingType = std::underlying_type_t<T>;
 67 |     return static_cast<T>(static_cast<UnderlyingType>(lhs) | static_cast<UnderlyingType>(rhs));
 68 | }
 69 | 
 70 | template <typename T, std::enable_if_t<std::is_enum_v<T> && zsl::IsFlagsV<T>, int> = 0>
 71 | constexpr auto operator^(T lhs, T rhs) -> T
 72 | {
 73 |     using UnderlyingType = std::underlying_type_t<T>;
 74 |     return static_cast<T>(static_cast<UnderlyingType>(lhs) | static_cast<UnderlyingType>(rhs));
 75 | }
 76 | 
 77 | template <typename T, std::enable_if_t<std::is_enum_v<T> && zsl::IsFlagsV<T>, int> = 0>
 78 | constexpr auto operator~(T lhs) -> T
 79 | {
 80 |     using UnderlyingType = std::underlying_type_t<T>;
 81 |     return static_cast<T>(~static_cast<UnderlyingType>(lhs));
 82 | }
 83 | 
 84 | template <typename T, std::enable_if_t<std::is_enum_v<T> && zsl::IsFlagsV<T>, int> = 0>
 85 | constexpr auto operator&=(T lhs, T rhs) -> T
 86 | {
 87 |     using UnderlyingType = std::underlying_type_t<T>;
 88 |     return lhs = static_cast<T>(static_cast<UnderlyingType>(lhs) & static_cast<UnderlyingType>(rhs));
 89 | }
 90 | 
 91 | template <typename T, std::enable_if_t<std::is_enum_v<T> && zsl::IsFlagsV<T>, int> = 0>
 92 | constexpr auto operator|=(T lhs, T rhs) -> T
 93 | {
 94 |     using UnderlyingType = std::underlying_type_t<T>;
 95 |     return lhs = static_cast<T>(static_cast<UnderlyingType>(lhs) | static_cast<UnderlyingType>(rhs));
 96 | }
 97 | 
 98 | template <typename T, std::enable_if_t<std::is_enum_v<T> && zsl::IsFlagsV<T>, int> = 0>
 99 | constexpr auto operator^=(T lhs, T rhs) -> T
100 | {
101 |     using UnderlyingType = std::underlying_type_t<T>;
102 |     return lhs = static_cast<T>(static_cast<UnderlyingType>(lhs) ^ static_cast<UnderlyingType>(rhs));
103 | }
104 | 


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