std::remove_reference

 

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定義於標頭檔案 <type_traits>
template< class T > struct remove_reference;		(C++11 起)

如果型別 T 是引用型別，則提供成員 typedef type，它是 T 所引用的型別。否則 type 是 T。

如果程式為 std::remove_reference 新增特化，則行為是未定義的。

成員型別

名稱	定義
型別	T 所引用的型別，如果 T 不是引用，則為 T

輔助型別

template< class T > using remove_reference_t = typename remove_reference<T>::type;		(C++14 起)

可能的實現

template<class T> struct remove_reference { typedef T type; }; template<class T> struct remove_reference<T&> { typedef T type; }; template<class T> struct remove_reference<T&&> { typedef T type; };

示例

執行此程式碼

#include <iostream>
#include <type_traits>
 
int main()
{
    std::cout << std::boolalpha;
 
    std::cout << "std::remove_reference<int>::type is int? "
              << std::is_same<int, std::remove_reference<int>::type>::value << '\n';
    std::cout << "std::remove_reference<int&>::type is int? "
              << std::is_same<int, std::remove_reference<int&>::type>::value << '\n';
    std::cout << "std::remove_reference<int&&>::type is int? "
              << std::is_same<int, std::remove_reference<int&&>::type>::value << '\n';
    std::cout << "std::remove_reference<const int&>::type is const int? "
              << std::is_same<const int,
                              std::remove_reference<const int&>::type>::value << '\n';
}

輸出

std::remove_reference<int>::type is int? true
std::remove_reference<int&>::type is int? true
std::remove_reference<int&&>::type is int? true
std::remove_reference<const int&>::type is const int? true

另請參閱

is_reference (C++11)	檢查型別是否為*左值引用*或*右值引用* (類模板)
add_lvalue_referenceadd_rvalue_reference (C++11)(C++11)	向給定型別新增左值或右值引用 (類模板)
remove_cvref (C++20)	結合了 std::remove_cv 和 std::remove_reference (類模板)