type_traits
标准库标头<type[医]性状>
此标头是类型支撑图书馆。
班
*。
帮助者类
积分[医]恒博[医]常数%28C++11%29%28C++17%29指定类型的编译时常数，指定值%28类模板%29
千真万确[医]STD类型：：整型[医]常数<bool，true>
假的[医]STD类型：：整型[医]常数<bool，false>
主要类型类别
是[医]空%28C++11%29检查一个类型是否为空%28类模板%29
是[医]零[医]指针%28C++14%29检查类型是否为std：：nullptr[医]T%28类模板%29
是[医]整数%28C++11%29检查类型是否为整型%28类模板%29
是[医]浮[医]点%28C++11%29检查类型是否为浮点数类型%28类模板%29
是[医]数组%28C++11%29检查类型是否为数组类型%28类模板%29
是[医]枚举%28C++11%29检查类型是否为枚举类型%28类模板%29
是[医]UNION%28C++11%29检查类型是否为联合类型%28类模板%29
是[医]类%28C++11%29检查某个类型是否为不合并类类型%28类模板%29。
是[医]函数%28C++11%29检查类型是否为函数类型%28类模板%29
是[医]指针%28C++11%29检查类型是否为指针类型%28类模板%29
是[医]洛值[医]引用%28C++11%29检查类型是否为lvalue引用%28class模板%29
是[医]r值[医]引用%28C++11%29检查类型是否为rvalue引用%28class模板%29
是[医]成员[医]对象[医]指针%28C++11%29检查类型是否是指向非静态成员对象%28类模板%29的指针。
是[医]成员[医]功能[医]指针%28C++11%29检查类型是否是指向非静态成员函数%28类模板%29的指针。
复合类型范畴
是[医]基本%28C++11%29检查一个类型是否是基本类型%28类模板%29
是[医]算术%28C++11%29检查一个类型是否是算术类型%28class模板%29
是[医]标量%28C++11%29检查类型是否为标量类型%28类模板%29
是[医]对象%28C++11%29检查类型是否为对象类型%28类模板%29
是[医]化合物%28C++11%29检查一个类型是否为复合类型%28类模板%29
是[医]引用%28C++11%29检查类型是否为lvalue引用或rvalue引用%28class模板%29
是[医]成员[医]指针%28C++11%29检查类型是否是指向非静态成员函数或对象%28类模板%29的指针。
类型属性
是[医]Const%28C++11%29检查类型是否为Const-合格%28类模板%29
是[医]挥发性%28C++11%29检查一个类型是否易失性-合格%28类模板%29
是[医]普通%28C++11%29检查类型是否为平凡%28类模板%29
是[医]琐碎[医]可复制%28C++11%29检查某类型是否可以复制%28类模板%29
是[医]标准[医]布局%28C++11%29检查某一类型是否为标准类型-布局类型%28类模板%29
是[医]POP%28C++11%29检查一个类型是否为旧数据%28POD%29类型%28class模板%29
是[医]文字[医]类型%28C++11%29%28在C++17%29中不建议使用，检查类型是否为文字类型%28class模板%29
有[医]独树一帜[医]对象[医]表示%28C++17%29检查类型%27s对象表示中的每一位是否有助于其值%28类模板%29
是[医]空的%28C++11%29检查类型是否为类%28，但不检查联合%29类型，并且没有数据%28类模板%29
是[医]多态%28C++11%29检查某一类型是否为多态类类型%28类模板%29
是[医]摘要%28C++11%29检查某个类型是否为抽象类类型%28类模板%29
是[医]最后%28C++14%29检查类型是否为最终类类型%28类模板%29
是[医]聚合%28C++17%29检查类型是否为聚合类型%28类模板%29
是[医]签名%28C++11%29检查类型是否有符号算术类型%28类模板%29
是[医]无符号%28C++11%29检查类型是否为无符号算术类型%28class模板%29
支助的业务
*。
是[医]构造性[医]琐碎[医]构造性[医]无抛[医]可构造的%28C++11%29%28C+11%29%28C+11%29检查类型是否具有特定参数的构造函数%28类模板%29
是[医]违约[医]构造性[医]琐碎[医]违约[医]构造性[医]无抛[医]违约[医]可构造的%28C++11%29%28C+11%29%28C+11%29检查类型是否具有默认构造函数%28类模板%29
是[医]复制[医]构造性[医]琐碎[医]复制[医]构造性[医]无抛[医]复制[医]可构造%28C++11%29%28C+11%29%28C+11%29检查类型是否具有复制构造函数%28class模板%29
是[医]移动[医]构造性[医]琐碎[医]移动[医]构造性[医]无抛[医]移动[医]可构造%28C++11%29%28C+11%29%28C+11%29检查是否可以从rvalue引用%28class模板%29构造类型
是[医]可分配[医]琐碎[医]可分配[医]无抛[医]可分配%28C++11%29%28C+11%29%28C+11%29检查类型是否有特定参数%28类模板%29的赋值运算符
是[医]复制[医]可分配[医]琐碎[医]复制[医]可分配[医]无抛[医]复制[医]可分配%28C++11%29%28C+11%29%28C+11%29检查类型是否有副本赋值操作符%28类模板%29
是[医]移动[医]可分配[医]琐碎[医]移动[医]可分配[医]无抛[医]移动[医]可分配%28C++11%29%28C+11%29%28C+11%29检查类型是否有移动赋值操作符%28class模板%29
是[医]破坏性[医]琐碎[医]破坏性[医]无抛[医]可销毁%28C+11%29%28C+11%29%28C+11%29检查类型是否具有非删除的析构函数%28类模板%29
有[医]虚拟[医]析构函数%28C++11%29检查类型是否具有虚拟析构函数%28类模板%29
是[医]可互换[医]威斯[医]可换[医]无抛[医]可互换[医]威斯[医]无抛[医]可交换%28C+17%29%28C+17%29%28C++17%29%28C+17%29检查类型的对象是否可以与相同或不同类型的对象交换%28class模板%29
属性查询
*。
对齐[医]%28C++11%29获得类型%27s对齐要求%28类模板%29
秩%28C++11%29获得数组类型的维数%28类模板%29
范围%28C++11%29沿指定维度%28类模板获得数组类型的大小
类型关系
*。
是[医]相同的%28C++11%29检查两种类型是否为相同的%28类模板%29
是[医]底座[医]在%28C++11%29中，检查类型是否派生自其他类型%28类模板%29
是[医]可转换%28C++11%29检查一个类型是否可以转换为其他类型%28class模板%29
是[医]可调用[医]可调用[医]RIS[医]无抛[医]可调用[医]无抛[医]可调用[医]r%28C++17%29检查一个类型是否可以通过std：：调用%29与给定的参数类型%28类模板%29
Const-挥发性说明符
移除[医]移除[医]移除[医]挥发性%28C++11%29%28C+11%29%28C+11%29从给定类型%28类模板%29中删除Const或/和挥发性说明符
加[医]cvadd[医]星座[医]挥发性%28C++11%29%28C+11%29%28C+11%29在给定类型%28类模板%29中添加Const或/和挥发性说明符
参考文献
移除[医]引用%28C++11%29从给定类型%28类模板%29中删除引用
加[医]洛值[医]参考添加[医]r值[医]引用%28C++11%29%28C++11%29向给定类型%28类模板%29添加lvalue或rvalue引用
指针
移除[医]指针%28C++11%29从给定类型%28类模板%29中删除指针
加[医]指针%28C++11%29将指针添加到给定类型%28类模板%29
符号修饰符
制造[医]有符号%28C++11%29使给定的整数类型有符号%28类模板%29
制造[医]无符号%28C++11%29使给定的整型无符号%28类模板%29
阵列
移除[医]范围%28C++11%29从给定数组类型%28类模板%29中删除一个区段
移除[医]全[医]区段%28C++11%29从给定数组类型%28类模板%29中删除所有区段
杂项变换
对齐[医]存储%28C++11%29将适合使用的类型定义为给定大小的类型的未初始化存储%28类模板%29
对齐[医]UNION%28C++11%29定义适合用于所有给定类型的未初始化存储类型%28类模板%29
衰变%28C++11%29在通过值%28类模板%29传递函数参数时应用类型转换
使能[医]如果%28C++11%29隐藏基于编译时布尔值%28类模板%29的函数重载或模板专门化
条件%28C++11%29基于编译类型boole%28 class模板%29选择一种类型或另一种类型。
共同[医]类型%28C++11%29确定类型组%28类模板%29的公共类型
底层[医]类型%28C++11%29获得给定枚举类型%28类模板%29的基础整数类型
结果[医]奥芬沃克[医]结果%28C++11%29%28在C++17%29%28C+17%29中不推荐使用一组参数%28类模板%29演绎调用可调用对象的结果类型
空隙[医]t%28C++17%29空可变别名模板%28别名模板%29
性状运算
连接%28C++17%29可变逻辑和元功能%28类模板%29
分离%28C++17%29可变逻辑或元功能%28类模板%29
否定%28C++17%29逻辑非元功能%28类模板%29
简介
二次
namespace std {
// helper class:
template <class T, T v> struct integral_constant;
template <bool B>
using bool_constant = integral_constant<bool, B>;
using true_type = bool_constant<true>;
using false_type = bool_constant<false>;
// primary type categories:
template <class T> struct is_void;
template <class T> struct is_null_pointer;
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;
// composite type categories:
template <class T> struct is_reference;
template <class T> struct is_arithmetic;
template <class T> struct is_fundamental;
template <class T> struct is_object;
template <class T> struct is_scalar;
template <class T> struct is_compound;
template <class T> struct is_member_pointer;
// type properties:
template <class T> struct is_const;
template <class T> struct is_volatile;
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_pod;
template <class T> struct is_empty;
template <class T> struct is_polymorphic;
template <class T> struct is_abstract;
template <class T> struct is_final;
template <class T> struct is_aggregate;
template <class T> struct is_signed;
template <class T> struct is_unsigned;
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;
template <class T> struct is_swappable;
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;
template <class T> struct is_nothrow_swappable;
template <class T> struct is_nothrow_destructible;
template <class T> struct has_virtual_destructor;
template <class T> struct has_unique_object_representations;
// type property queries:
template <class T> struct alignment_of;
template <class T> struct rank;
template <class T, unsigned I = 0> struct extent;
// type relations:
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 <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;
// const-volatile modifications:
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;
template <class T>
using remove_const_t = typename remove_const<T>::type;
template <class T>
using remove_volatile_t = typename remove_volatile<T>::type;
template <class T>
using remove_cv_t = typename remove_cv<T>::type;
template <class T>
using add_const_t = typename add_const<T>::type;
template <class T>
using add_volatile_t = typename add_volatile<T>::type;
template <class T>
using add_cv_t = typename add_cv<T>::type;
// reference modifications:
template <class T> struct remove_reference;
template <class T> struct add_lvalue_reference;
template <class T> struct add_rvalue_reference;
template <class T>
using remove_reference_t = typename remove_reference<T>::type;
template <class T>
using add_lvalue_reference_t = typename add_lvalue_reference<T>::type;
template <class T>
using add_rvalue_reference_t = typename add_rvalue_reference<T>::type;
// sign modifications:
template <class T> struct make_signed;
template <class T> struct make_unsigned;
template <class T>
using make_signed_t = typename make_signed<T>::type;
template <class T>
using make_unsigned_t = typename make_unsigned<T>::type;
// array modifications:
template <class T> struct remove_extent;
template <class T> struct remove_all_extents;
template <class T>
using remove_extent_t = typename remove_extent<T>::type;
template <class T>
using remove_all_extents_t = typename remove_all_extents<T>::type;
// pointer modifications:
template <class T> struct remove_pointer;
template <class T> struct add_pointer;
template <class T>
using remove_pointer_t = typename remove_pointer<T>::type;
template <class T>
using add_pointer_t = typename add_pointer<T>::type;
// other transformations:
template <size_t Len,
size_t Align = /*default-alignment*/ >
struct aligned_storage;
template <size_t Len, class... Types> struct aligned_union;
template <class T> struct decay;
template <bool, class T = void> struct enable_if;
template <bool, class T, class F> struct conditional;
template <class... T> struct common_type;
template <class T> struct underlying_type;
template <class> class result_of; // not defined
template <class F, class... ArgTypes> class result_of<F(ArgTypes...)>;
template <class F, class... ArgTypes> class invoke_result;
template <size_t Len,
size_t Align = /*default-alignment*/ >
using aligned_storage_t = typename aligned_storage<Len, Align>::type;
template <size_t Len, class... Types>
using aligned_union_t = typename aligned_union<Len, Types...>::type;
template <class T>
using decay_t = typename decay<T>::type;
template <bool b, class T = void>
using enable_if_t = typename enable_if<b, T>::type;
template <bool b, class T, class F>
using conditional_t = typename conditional<b, T, F>::type;
template <class... T>
using common_type_t = typename common_type<T...>::type;
template <class T>
using underlying_type_t = typename underlying_type<T>::type;
template <class T>
using result_of_t = typename result_of<T>::type;
template <class F, class... ArgTypes>
using invoke_result_t = typename invoke_result<F, ArgTypes...>::type;
template <class...>
using void_t = void;
// logical operator traits:
template<class... B> struct conjunction;
template<class... B> struct disjunction;
template<class B> struct negation;
// primary type categories
template <class T> inline constexpr bool is_void_v
= is_void<T>::value;
template <class T> inline constexpr bool is_null_pointer_v
= is_null_pointer<T>::value;
template <class T> inline constexpr bool is_integral_v
= is_integral<T>::value;
template <class T> inline constexpr bool is_floating_point_v
= is_floating_point<T>::value;
template <class T> inline constexpr bool is_array_v
= is_array<T>::value;
template <class T> inline constexpr bool is_pointer_v
= is_pointer<T>::value;
template <class T> inline constexpr bool is_lvalue_reference_v
= is_lvalue_reference<T>::value;
template <class T> inline constexpr bool is_rvalue_reference_v
= is_rvalue_reference<T>::value;
template <class T> inline constexpr bool is_member_object_pointer_v
= is_member_object_pointer<T>::value;
template <class T> inline constexpr bool is_member_function_pointer_v
= is_member_function_pointer<T>::value;
template <class T> inline constexpr bool is_enum_v
= is_enum<T>::value;
template <class T> inline constexpr bool is_union_v
= is_union<T>::value;
template <class T> inline constexpr bool is_class_v
= is_class<T>::value;
template <class T> inline constexpr bool is_function_v
= is_function<T>::value;
// composite type categories
template <class T> inline constexpr bool is_reference_v
= is_reference<T>::value;
template <class T> inline constexpr bool is_arithmetic_v
= is_arithmetic<T>::value;
template <class T> inline constexpr bool is_fundamental_v
= is_fundamental<T>::value;
template <class T> inline constexpr bool is_object_v
= is_object<T>::value;
template <class T> inline constexpr bool is_scalar_v
= is_scalar<T>::value;
template <class T> inline constexpr bool is_compound_v
= is_compound<T>::value;
template <class T> inline constexpr bool is_member_pointer_v
= is_member_pointer<T>::value;
// type properties
template <class T> inline constexpr bool is_const_v
= is_const<T>::value;
template <class T> inline constexpr bool is_volatile_v
= is_volatile<T>::value;
template <class T> inline constexpr bool is_trivial_v
= is_trivial<T>::value;
template <class T> inline constexpr bool is_trivially_copyable_v
= is_trivially_copyable<T>::value;
template <class T> inline constexpr bool is_standard_layout_v
= is_standard_layout<T>::value;
template <class T> inline constexpr bool is_pod_v
= is_pod<T>::value;
template <class T> inline constexpr bool is_empty_v
= is_empty<T>::value;
template <class T> inline constexpr bool is_polymorphic_v
= is_polymorphic<T>::value;
template <class T> inline constexpr bool is_abstract_v
= is_abstract<T>::value;
template <class T> inline constexpr bool is_final_v
= is_final<T>::value;
template <class T> inline constexpr bool is_aggregate_v
= is_aggregate<T>::value;
template <class T> inline constexpr bool is_signed_v
= is_signed<T>::value;
template <class T> inline constexpr bool is_unsigned_v
= is_unsigned<T>::value;
template <class T, class... Args> inline constexpr bool is_constructible_v
= is_constructible<T, Args...>::value;
template <class T> inline constexpr bool is_default_constructible_v
= is_default_constructible<T>::value;
template <class T> inline constexpr bool is_copy_constructible_v
= is_copy_constructible<T>::value;
template <class T> inline constexpr bool is_move_constructible_v
= is_move_constructible<T>::value;
template <class T, class U> inline constexpr bool is_assignable_v
= is_assignable<T, U>::value;
template <class T> inline constexpr bool is_copy_assignable_v
= is_copy_assignable<T>::value;
template <class T> inline constexpr bool is_move_assignable_v
= is_move_assignable<T>::value;
template <class T, class U> inline constexpr bool is_swappable_with_v
= is_swappable_with<T, U>::value;
template <class T> inline constexpr bool is_swappable_v
= is_swappable<T>::value;
template <class T> inline constexpr bool is_destructible_v
= is_destructible<T>::value;
template <class T, class... Args> inline constexpr bool is_trivially_constructible_v
= is_trivially_constructible<T, Args...>::value;
template <class T> inline constexpr bool is_trivially_default_constructible_v
= is_trivially_default_constructible<T>::value;
template <class T> inline constexpr bool is_trivially_copy_constructible_v
= is_trivially_copy_constructible<T>::value;
template <class T> inline constexpr bool is_trivially_move_constructible_v
= is_trivially_move_constructible<T>::value;
template <class T, class U> inline constexpr bool is_trivially_assignable_v
= is_trivially_assignable<T, U>::value;
template <class T> inline constexpr bool is_trivially_copy_assignable_v
= is_trivially_copy_assignable<T>::value;
template <class T> inline constexpr bool is_trivially_move_assignable_v
= is_trivially_move_assignable<T>::value;
template <class T> inline constexpr bool is_trivially_destructible_v
= is_trivially_destructible<T>::value;
template <class T, class... Args> inline constexpr bool is_nothrow_constructible_v
= is_nothrow_constructible<T, Args...>::value;
template <class T> inline constexpr bool is_nothrow_default_constructible_v
= is_nothrow_default_constructible<T>::value;
template <class T> inline constexpr bool is_nothrow_copy_constructible_v
= is_nothrow_copy_constructible<T>::value;
template <class T> inline constexpr bool is_nothrow_move_constructible_v
= is_nothrow_move_constructible<T>::value;
template <class T, class U> inline constexpr bool is_nothrow_assignable_v
= is_nothrow_assignable<T, U>::value;
template <class T> inline constexpr bool is_nothrow_copy_assignable_v
= is_nothrow_copy_assignable<T>::value;
template <class T> inline constexpr bool is_nothrow_move_assignable_v
= is_nothrow_move_assignable<T>::value;
template <class T, class U> inline constexpr bool is_nothrow_swappable_with_v
= is_nothrow_swappable_with<T, U>::value;
template <class T> inline constexpr bool is_nothrow_swappable_v
= is_nothrow_swappable<T>::value;
template <class T> inline constexpr bool is_nothrow_destructible_v
= is_nothrow_destructible<T>::value;
template <class T> inline constexpr bool has_virtual_destructor_v
= has_virtual_destructor<T>::value;
template <class T> inline constexpr bool has_unique_object_representations_v
= has_unique_object_representations<T>::value;
// type property queries
template <class T> inline constexpr size_t alignment_of_v
= alignment_of<T>::value;
template <class T> inline constexpr size_t rank_v
= rank<T>::value;
template <class T, unsigned I = 0> inline constexpr size_t extent_v
= extent<T, I>::value;
// type relations
template <class T, class U> inline constexpr bool is_same_v
= is_same<T, U>::value;
template <class Base, class Derived> inline constexpr bool is_base_of_v
= is_base_of<Base, Derived>::value;
template <class From, class To> inline constexpr bool is_convertible_v
= is_convertible<From, To>::value;
template <class Fn, class... ArgTypes>
inline constexpr bool is_invocable_v
= is_invocable<Fn, ArgTypes...>::value;
template <class R, class Fn, class... ArgTypes>
inline constexpr bool is_invocable_r_v
= is_invocable_r<R, Fn, ArgTypes...>::value;
template <class Fn, class... ArgTypes>
inline constexpr bool is_nothrow_invocable_v
= is_nothrow_invocable<Fn, ArgTypes...>::value;
template <class R, class Fn, class... ArgTypes>
inline constexpr bool is_nothrow_invocable_r_v
= is_nothrow_invocable_r<R, Fn, ArgTypes...>::value;
// logical operator traits:
template<class... B> inline constexpr bool conjunction_v = conjunction<B...>::value;
template<class... B> inline constexpr bool disjunction_v = disjunction<B...>::value;
template<class B> inline constexpr bool negation_v = negation<B>::value;
} // namespace std
二次
类std::integral_constant
二次
namespace std {
template <class T, T v>
struct integral_constant {
static constexpr T value = v;
using value_type = T;
using type = integral_constant<T, v>;
constexpr operator value_type() const noexcept { return value; }
constexpr value_type operator()() const noexcept { return value; }
};
}
二次
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