std::has_virtual_destructor

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C++
 
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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）
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is_constructible
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（C++11）
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is_move_constructible
is_trivially_move_constructible
is_nothrow_move_constructible		（C++11）
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is_assignable
is_trivially_assignable
is_nothrow_assignable		（C++11）
（C++11）
（C++11）
is_copy_assignable
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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）
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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 has_virtual_destructor;
 （C++11 起）
如果T是一种虚析构函数，成员常量valuetrue平等。对于任何其他类型，value是false.
Original:
If T is a type with a virtual destructor, provides the member constant value equal true. For any other type, value is false.
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目录

Inherited from std::integral_constant

Member constants

value
[静态的] </ SPAN></div></div>
true如果 T has a virtual destructor ，false其他方式
Original:
true if T has a virtual destructor , 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

如果一个类有一个公有虚析构函数，它可以派生，派生类对象可以通过指针被安全地删除的基本对象（C++FAQ Lite 20.7）
Original:
If a class has a public virtual destructor, it can be derived from, and the derived object can be safely deleted through a pointer to the base object (C++FAQ Lite 20.7)
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[编辑] 为例

#include <iostream>
#include <type_traits>
#include <string>
#include <stdexcept>
 
int main()
{
    std::cout << std::boolalpha
              << "std::string has a virtual destructor? "
              << std::has_virtual_destructor<std::string>::value << '\n'
              << "std::runtime_error has a virtual destructor? "
              << std::has_virtual_destructor<std::runtime_error>::value << '\n';
}

Output: 

std::string has a virtual destructor? false
std::runtime_error has a virtual destructor? true

[编辑] 另请参阅

（C++11）
（C++11）
（C++11）
如果一个类型的检查，具有不可删除的析构函数
Original:
checks if a type has a non-deleted destructor
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（类模板） [edit]
来自“http://zh.cppreference.com/mwiki/index.php?title=cpp/types/has_virtual_destructor&oldid=27612”