Line data    Source code

       1            0 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : #pragma once
       5              : 
       6              : #include <type_traits>
       7              : 
       8              : namespace tt {
       9              : /// @{
      10              : /// \ingroup TypeTraitsGroup
      11              : /// \brief Check if type `T` has operator!= defined.
      12              : ///
      13              : /// \details
      14              : /// Inherits from std::true_type if the type `T` has operator!= defined,
      15              : /// otherwise inherits from std::false_type
      16              : ///
      17              : /// \usage
      18              : /// For any type `T`,
      19              : /// \code
      20              : /// using result = tt::has_inequivalence<T>;
      21              : /// \endcode
      22              : ///
      23              : /// \metareturns
      24              : /// std::bool_constant
      25              : ///
      26              : /// \semantics
      27              : /// If the type `T` has operator!= defined, then
      28              : /// \code
      29              : /// typename result::type = std::true_type;
      30              : /// \endcode
      31              : /// otherwise
      32              : /// \code
      33              : /// typename result::type = std::false_type;
      34              : /// \endcode
      35              : ///
      36              : /// \example
      37              : /// \snippet Test_HasInequivalence.cpp has_inequivalence_example
      38              : /// \see has_equivalence
      39              : /// \tparam T the type we want to know if it has operator!=
      40              : template <typename T, typename U = void>
      41            1 : struct has_inequivalence : std::false_type {};
      42              : 
      43              : /// \cond HIDDEN_SYMBOLS
      44              : template <typename T>
      45              : struct has_inequivalence<
      46              :     T, std::void_t<decltype(std::declval<T>() != std::declval<T>())>>
      47              :     : std::true_type {};
      48              : /// \endcond
      49              : 
      50              : /// \see has_inequivalence
      51              : template <typename T>
      52            1 : constexpr bool has_inequivalence_v = has_inequivalence<T>::value;
      53              : 
      54              : /// \see has_inequivalence
      55              : template <typename T>
      56            1 : using has_inequivalence_t = typename has_inequivalence<T>::type;
      57              : /// @}
      58              : }  // namespace tt