Utilities/std/cmext/type_traits

// -*-c++-*-
// vim: set ft=cpp:

/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing for details.  */
#pragma once

#include <memory>

#include <cm/type_traits>

namespace cm {

#if defined(__SUNPRO_CC)
// Oracle DeveloperStudio C++ compiler do not support overloaded templates with
// same signature but different constraints over template arguments
// (i.e. meta-programming).
// As a work-around, use a structure to avoid templates with same signature.
namespace detail {
template <int N>
struct overload_selector : overload_selector<N - 1>
{
};

template <>
struct overload_selector<0>
{
};
}
#endif

// type traits for managed pointer types
template <typename>
struct is_unique_ptr : std::false_type
{
};
template <typename T>
struct is_unique_ptr<std::unique_ptr<T>> : std::true_type
{
};

// type traits for containers
template <typename, typename = void_t<>>
struct is_container : std::false_type
{
};
template <typename T>
struct is_container<
  T,
  cm::void_t<typename T::value_type, typename T::size_type,
             typename T::difference_type, typename T::iterator>>
  : std::true_type
{
};

template <typename, typename = void_t<>>
struct is_associative_container : std::false_type
{
};
template <typename T>
struct is_associative_container<
  T, cm::void_t<typename T::key_type, typename T::key_compare>>
  : cm::is_container<T>
{
};

template <typename, typename = void_t<>>
struct is_unordered_associative_container : std::false_type
{
};
template <typename T>
struct is_unordered_associative_container<
  T,
  cm::void_t<typename T::key_type, typename T::hasher, typename T::key_equal,
             typename T::local_iterator>> : cm::is_container<T>
{
};

template <typename T>
using is_sequence_container =
  cm::bool_constant<cm::is_container<T>::value &&
                    !cm::is_associative_container<T>::value &&
                    !cm::is_unordered_associative_container<T>::value>;

} // namespace cm