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type_traits

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

代码语言：javascript
复制
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

代码语言：javascript
复制
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

代码语言：txt
复制
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