为什么允许通过常量引用而不是通过普通引用传递 R 值?
下面的程序
void display(const int& a)
{
cout << a ;
}
如果使用这样的文字调用将起作用
will work if called with a literal like this
display(5);
但如果没有 const
它将无法工作.
but without the const
it won't work.
那么 const
引用如何一直指向 R 值(匿名变量)?
So how can a const
reference keep pointing to an R-Value (anonymous variable)?
推荐答案
最后一个问题:
const 引用如何一直指向 R 值(匿名变量)
how can a?const?reference keep pointing to an R-Value (anonymous variable)
这里是回答.C++ 语言说局部常量引用会延长临时值的生命周期,直到包含范围结束,但可以节省复制构造的成本(即,如果您要使用局部变量).
Here is the answer. The C++ language says that a local const reference prolongs the lifetime of temporary values until the end of the containing scope, but saving you the cost of a copy-construction (i.e. if you were to use an local variable instead).
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