// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_TYPE_TRAITS
#define _LIBCPP_TYPE_TRAITS

/*
    type_traits synopsis

namespace std
{

    // helper class:
    template <class T, T v> struct integral_constant;
    typedef integral_constant<bool, true>  true_type;   // C++11
    typedef integral_constant<bool, false> false_type;  // C++11

    template <bool B>                                   // C++14
    using bool_constant = integral_constant<bool, B>;   // C++14
    typedef bool_constant<true> true_type;              // C++14
    typedef bool_constant<false> false_type;            // C++14

    // helper traits
    template <bool, class T = void> struct enable_if;
    template <bool, class T, class F> struct conditional;

    // Primary classification traits:
    template <class T> struct is_void;
    template <class T> struct is_null_pointer;  // C++14
    template <class T> struct is_integral;
    template <class T> struct is_floating_point;
    template <class T> struct is_array;
    template <class T> struct is_pointer;
    template <class T> struct is_lvalue_reference;
    template <class T> struct is_rvalue_reference;
    template <class T> struct is_member_object_pointer;
    template <class T> struct is_member_function_pointer;
    template <class T> struct is_enum;
    template <class T> struct is_union;
    template <class T> struct is_class;
    template <class T> struct is_function;

    // Secondary classification traits:
    template <class T> struct is_reference;
    template <class T> struct is_arithmetic;
    template <class T> struct is_fundamental;
    template <class T> struct is_member_pointer;
    template <class T> struct is_scoped_enum; // C++23
    template <class T> struct is_scalar;
    template <class T> struct is_object;
    template <class T> struct is_compound;

    // Const-volatile properties and transformations:
    template <class T> struct is_const;
    template <class T> struct is_volatile;
    template <class T> struct remove_const;
    template <class T> struct remove_volatile;
    template <class T> struct remove_cv;
    template <class T> struct add_const;
    template <class T> struct add_volatile;
    template <class T> struct add_cv;

    // Reference transformations:
    template <class T> struct remove_reference;
    template <class T> struct add_lvalue_reference;
    template <class T> struct add_rvalue_reference;

    // Pointer transformations:
    template <class T> struct remove_pointer;
    template <class T> struct add_pointer;

    template<class T> struct type_identity;                     // C++20
    template<class T>
      using type_identity_t = typename type_identity<T>::type;  // C++20

    // Integral properties:
    template <class T> struct is_signed;
    template <class T> struct is_unsigned;
    template <class T> struct make_signed;
    template <class T> struct make_unsigned;

    // Array properties and transformations:
    template <class T> struct rank;
    template <class T, unsigned I = 0> struct extent;
    template <class T> struct remove_extent;
    template <class T> struct remove_all_extents;

    template <class T> struct is_bounded_array;                 // C++20
    template <class T> struct is_unbounded_array;               // C++20

    // Member introspection:
    template <class T> struct is_pod;
    template <class T> struct is_trivial;
    template <class T> struct is_trivially_copyable;
    template <class T> struct is_standard_layout;
    template <class T> struct is_literal_type; // Deprecated in C++17; removed in C++20
    template <class T> struct is_empty;
    template <class T> struct is_polymorphic;
    template <class T> struct is_abstract;
    template <class T> struct is_final; // C++14
    template <class T> struct is_aggregate; // C++17

    template <class T, class... Args> struct is_constructible;
    template <class T>                struct is_default_constructible;
    template <class T>                struct is_copy_constructible;
    template <class T>                struct is_move_constructible;
    template <class T, class U>       struct is_assignable;
    template <class T>                struct is_copy_assignable;
    template <class T>                struct is_move_assignable;
    template <class T, class U>       struct is_swappable_with;       // C++17
    template <class T>                struct is_swappable;            // C++17
    template <class T>                struct is_destructible;

    template <class T, class... Args> struct is_trivially_constructible;
    template <class T>                struct is_trivially_default_constructible;
    template <class T>                struct is_trivially_copy_constructible;
    template <class T>                struct is_trivially_move_constructible;
    template <class T, class U>       struct is_trivially_assignable;
    template <class T>                struct is_trivially_copy_assignable;
    template <class T>                struct is_trivially_move_assignable;
    template <class T>                struct is_trivially_destructible;

    template <class T, class... Args> struct is_nothrow_constructible;
    template <class T>                struct is_nothrow_default_constructible;
    template <class T>                struct is_nothrow_copy_constructible;
    template <class T>                struct is_nothrow_move_constructible;
    template <class T, class U>       struct is_nothrow_assignable;
    template <class T>                struct is_nothrow_copy_assignable;
    template <class T>                struct is_nothrow_move_assignable;
    template <class T, class U>       struct is_nothrow_swappable_with; // C++17
    template <class T>                struct is_nothrow_swappable;      // C++17
    template <class T>                struct is_nothrow_destructible;

    template <class T> struct has_virtual_destructor;

    template<class T> struct has_unique_object_representations;         // C++17

    // Relationships between types:
    template <class T, class U> struct is_same;
    template <class Base, class Derived> struct is_base_of;

    template <class From, class To> struct is_convertible;
    template <typename From, typename To> struct is_nothrow_convertible;                  // C++20
    template <typename From, typename To> inline constexpr bool is_nothrow_convertible_v; // C++20

    template <class Fn, class... ArgTypes> struct is_invocable;
    template <class R, class Fn, class... ArgTypes> struct is_invocable_r;

    template <class Fn, class... ArgTypes> struct is_nothrow_invocable;
    template <class R, class Fn, class... ArgTypes> struct is_nothrow_invocable_r;

    // Alignment properties and transformations:
    template <class T> struct alignment_of;
    template <size_t Len, size_t Align = most_stringent_alignment_requirement>
        struct aligned_storage;                                 // deprecated in C++23
    template <size_t Len, class... Types> struct aligned_union; // deprecated in C++23
    template <class T> struct remove_cvref; // C++20

    template <class T> struct decay;
    template <class... T> struct common_type;
    template <class T> struct underlying_type;
    template <class> class result_of; // undefined; deprecated in C++17; removed in C++20
    template <class Fn, clas                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    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