std::is_literal_type

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C++
 
实用工具库
类型的支持 (basic types, RTTI, type traits)
动态内存管理
错误处理
程序实用工具
可变参数函数
日期和时间
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initializer_list（C++11）
bitset
hash（C++11）
关系运算符
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Relational operators
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rel_ops::operator!=
rel_ops::operator>
rel_ops::operator<=
rel_ops::operator>=
双和元组
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Pairs and tuples
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pair
tuple（C++11）
piecewise_construct_t（C++11）
piecewise_construct（C++11）
掉期，远期和移动
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Swap, forward and move
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swap
forward（C++11）
move（C++11）
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declval（C++11）
 
类型的支持
基本类型
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Basic types
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基本类型
固定宽度的整数类型 （C++11）
nullptr_t（C++11）
offsetof
NULL
数值范围内
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Numeric limits
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C数字限制接口
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Runtime type information
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类型特征
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Type traits
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初级型两类
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Primary type categories
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is_void（C++11）
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is_function（C++11）
is_object（C++11）
is_scalar（C++11）
is_compound（C++11）
is_integral（C++11）
is_floating_point（C++11）
is_fundamental（C++11）
is_arithmetic（C++11）
is_reference（C++11）
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is_rvalue_reference（C++11）
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is_member_object_pointer（C++11）
is_member_function_pointer（C++11）
类型属性
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Type properties
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is_const（C++11）
is_volatile（C++11）
is_pod（C++11）
is_empty（C++11）
is_polymorphic（C++11）
is_abstract（C++11）
is_trivial（C++11）
is_trivially_copyable（C++11）
is_standard_layout（C++11）
is_literal_type（C++11）
is_signed（C++11）
is_unsigned（C++11）
支持的操作
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Supported operations
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is_constructible
is_trivially_constructible
is_nothrow_constructible		（C++11）
（C++11）
（C++11）
is_default_constructible
is_trivially_default_constructible
is_nothrow_default_constructible		（C++11）
（C++11）
（C++11）
is_copy_constructible
is_trivially_copy_constructible
is_nothrow_copy_constructible		（C++11）
（C++11）
（C++11）
is_move_constructible
is_trivially_move_constructible
is_nothrow_move_constructible		（C++11）
（C++11）
（C++11）
is_assignable
is_trivially_assignable
is_nothrow_assignable		（C++11）
（C++11）
（C++11）
is_copy_assignable
is_trivially_copy_assignable
is_nothrow_copy_assignable		（C++11）
（C++11）
（C++11）
is_move_assignable
is_trivially_move_assignable
is_nothrow_move_assignable		（C++11）
（C++11）
（C++11）
is_destructible
is_trivially_destructible
is_nothrow_destructible		（C++11）
（C++11）
（C++11）
has_virtual_destructor（C++11）
关系和属性查询
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Relationships and property queries
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is_same（C++11）
is_base_of（C++11）
is_convertible（C++11）
alignment_of（C++11）
rank（C++11）
extent（C++11）
类型的修改
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Type modifications
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remove_cv
remove_const
remove_volatile		（C++11）
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add_cv
add_const
add_volatile		（C++11）
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（C++11）
make_signed（C++11）
make_unsigned（C++11）
remove_reference（C++11）
add_lvalue_reference
add_rvalue_reference		（C++11）
（C++11）
remove_pointer（C++11）
add_pointer（C++11）
remove_extent（C++11）
remove_all_extents（C++11）
类型转换
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Type transformations
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aligned_storage（C++11）
aligned_union（C++11）
decay（C++11）
enable_if（C++11）
conditional（C++11）
common_type（C++11）
underlying_type（C++11）
result_of（C++11）
键入特征常数
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Type trait constants
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integral_constant（C++11）
 
Defined in header <type_traits>
template< class T >
struct is_literal_type;
 （C++11 起）
T是文本类型，提供成员value等于true。对于任何其他类型，value是false.
Original:
If T is a literal type, provides the member constant value equal true. For any other type, value is false.
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文本类型是任何标量类型，任何引用类型或类类型
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A literal type is any scalar type, any reference type or a class type that:
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1。有一个平凡的析构函数
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1. has a trivial destructor
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2。它的构造函数调用的非静态数据成员的初始化是常量表达式
Original:
2. all of its constructor calls and initializers for nonstatic data members are constant expressions
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3。是一个聚合类型，或至少有一个是复制或移动的构造constexpr构造函数
Original:
3. is an aggregate type or has at least one constexpr constructor that is not a copy or move constructor
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4。所有的非静态数据成员和基类是文本类型
Original:
4. all of its nonstatic data members and base classes are literal types
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文字类型的数组也是一个文本类型.
Original:
An array of literal types is also a literal type.
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目录

Inherited from std::integral_constant

Member constants

value
[静态的] </ SPAN></div></div>
true如果T is a literal type，false其他方式
Original:
true if T is a literal type, false otherwise
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（公共静态成员常量）

Member functions

operator bool
转换的对象bool，返回value
Original:
converts the object to bool, returns value
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（公共成员函数）

Member types

类型
Original:
Type
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 Definition
value_type bool
type std::integral_constant<bool, value>

</div>

[编辑] 注释

只有文本类型可以作为参数来使用，或返回从constexpr功能。只有文字类可能有constexpr的成员函数.
Original:
Only literal types may be used as parameters to or returned from constexpr functions. Only literal classes may have constexpr member functions.
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[编辑] 为例

#include <iostream>
#include <type_traits>
 
struct A {
    int m;
};
 
struct B {
    virtual ~B();
};
 
int main()
{
    std::cout << std::boolalpha;
    std::cout << std::is_literal_type<A>::value << '\n';
    std::cout << std::is_literal_type<B>::value << '\n';
}

Output: 

true
false
来自“http://zh.cppreference.com/mwiki/index.php?title=cpp/types/is_literal_type&oldid=27430”