std::bad_cast

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C++
 
实用工具库
类型的支持 (basic types, RTTI, type traits)
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initializer_list（C++11）
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关系运算符
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rel_ops::operator!=
rel_ops::operator>
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rel_ops::operator>=
双和元组
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Pairs and tuples
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pair
tuple（C++11）
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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）
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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）
nullptr_t（C++11）
offsetof
NULL
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numeric_limits
C数字限制接口
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Runtime type information
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type_info
type_index（C++11）
bad_typeid
bad_cast
类型特征
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Type properties
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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）
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Relationships and property queries
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remove_cv
remove_const
remove_volatile		（C++11）
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add_cv
add_const
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make_signed（C++11）
make_unsigned（C++11）
remove_reference（C++11）
add_lvalue_reference
add_rvalue_reference		（C++11）
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add_pointer（C++11）
remove_extent（C++11）
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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）
 
std::bad_cast
成员函数
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Member functions
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bad_cast::bad_cast
继承自std::exception
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Inherited from std::exception
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exception::~exception
exception::what
 
Defined in header <typeinfo>
class bad_cast : public std::exception;
dynamic_cast为引用类型时，抛出这种类型的异常运行时检查（例如，因为继承的类型是不相关的）失败.
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An exception of this type is thrown when a dynamic_cast to a reference type fails the run-time check (e.g. because the types are not related by inheritance).
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cpp/error/exceptionstd-bad cast-inheritance.svg
关于这幅图像

Inheritance diagram

目录

[编辑] 成员函数
构造一个新的bad_cast对象
Original:
constructs a new bad_cast object
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（公共成员函数）

Inherited from std::exception

Member functions

[虚拟的] </ SPAN></div></div>
解构异常对象
Original:
destructs the exception object
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（虚拟公有成员函数of std::exception） [edit]
[虚拟的] </ SPAN></div></div>
返回一个说明字符串
Original:
returns an explanatory string
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（虚拟公有成员函数of std::exception） [edit]

</div>

[编辑] 为例

#include <iostream>
#include <typeinfo>
 
struct Foo { virtual void f() {} };
struct Bar { virtual void f() {} };
 
int main()
{
    Bar b;
    try {
        Foo& f = dynamic_cast<Foo&>(b);
    } catch(const std::bad_cast& e)
    {
        std::cout << e.what() << '\n';
    }
}

Output: 

Bad dynamic_cast!

来自“http://zh.cppreference.com/mwiki/index.php?title=cpp/types/bad_cast&oldid=27702”