字面值和右值引用 [英] literal and rvalue reference

问题描述

void test(int && val)
{
    val=4;
}

void main()
{  
    test(1);
    std::cin.ignore();    
}

是 int 当调用 test 或在c ++文字中默认为 int 类型时创建？

Is a int is created when test is called or by default in c++ literals are int type?

推荐答案

请注意，您的代码将使用C ++ 11编译器编译 only 。

Note that your code would compile only with C++11 compiler.

当你传递一个默认为 int 类型的整数文字时，除非你写 1L ，创建类型为 int 的临时对象，它绑定到函数的参数。它就像下面初始化中的第一：

When you pass an integral literal, which is by default of int type, unless you write 1L, a temporary object of type int is created which is bound to the parameter of the function. It's like the first from the following initializations:

int &&      x = 1; //ok. valid in C++11 only.
int &       y = 1; //error, both in C++03, and C++11
const int & z = 1; //ok, both in C++03, and C++11

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