src/cpp-common/bt2c/type-traits.hpp

   1 /*
   2  * Copyright (c) 2023 Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * SPDX-License-Identifier: MIT
   5  */
   6
   7 #ifndef BABELTRACE_CPP_COMMON_BT2C_TYPE_TRAITS_HPP
   8 #define BABELTRACE_CPP_COMMON_BT2C_TYPE_TRAITS_HPP
   9
  10 #include <type_traits>
  11
  12 namespace bt2c {
  13
  14 /*
  15  * Provides the member constant `value` equal to:
  16  *
  17  * `T` is in the list of types `Ts`:
  18  *     `true`
  19  *
  20  * Otherwise:
  21  *     `false`
  22  */
  23 template <typename T, typename... Ts>
  24 struct IsOneOf : std::false_type
  25 {
  26 };
  27
  28 template <typename T, typename... Ts>
  29 struct IsOneOf<T, T, Ts...> : std::true_type
  30 {
  31 };
  32
  33 template <typename T, typename U, typename... Ts>
  34 struct IsOneOf<T, U, Ts...> : IsOneOf<T, Ts...>
  35 {
  36 };
  37
  38 } /* namespace bt2c */
  39
  40 #endif /* BABELTRACE_CPP_COMMON_BT2C_TYPE_TRAITS_HPP */