std::remove_all_extents

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C++
 
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remove_extent（C++11）
remove_all_extents（C++11）
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Defined in header <type_traits>
template< class T >
struct remove_all_extents;
 （C++11 起）
如果T是一个多维数组的某些类型X，成员typedeftype等于X，否则type是T.
Original:
If T is a multidimensional array of some type X, provides the member typedef type equal to X, otherwise type is T.
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目录

[编辑] 会员类型

姓名
Original:
Name
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 Definition
type
T的元素的类型
Original:
the type of the element of T
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[编辑] 可能的实现

template<class T>
struct remove_all_extents { typedef T type;};
 
template<class T>
struct remove_all_extents<T[]> {
    typedef typename remove_all_extents<T>::type type;
};
 
template<class Tp, std::size_t N>
struct remove_all_extents<T[N]> {
    typedef typename remove_all_extents<T>::type type;
};

[编辑] 为例

#include <iostream>
#include <type_traits>
#include <typeinfo>
 
template<class A>
void foo(const A&)
{
    typedef typename std::remove_all_extents<A>::type Type;
    std::cout << "underlying type: " << typeid(Type).name() << '\n';
}
 
int main()
{
    float a1[1][2][3];
    int a2[3][2];
    float a3[1][1][1][1][2];
    double a4[2][3];
 
    foo(a1);
    foo(a2);
    foo(a3);
    foo(a4);
}

Output: 

underlying type: f
underlying type: i
underlying type: f
underlying type: d

[编辑] 另请参阅

（C++11）
检查如果一个类型是数组类型
Original:
checks if a type is an array type
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（类模板） [edit]
（C++11）
获得一个数组类型的尺寸
Original:
obtains the number of dimensions of an array type
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（类模板） [edit]
（C++11）
获得一个数组类型的大小，沿着指定的尺寸
Original:
obtains the size of an array type along a specified dimension
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（类模板） [edit]
（C++11）
删除一个程度上给定的数组类型
Original:
removes one extent from the given array type
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（类模板） [edit]
来自“http://zh.cppreference.com/mwiki/index.php?title=cpp/types/remove_all_extents&oldid=26806”