c++规定指向临时变量的引用只能为常数,具体看看代码了
什么是临时变量又怎么产生的呢,可以看看一下代码
void f(short const & b)
...{}
int _tmain(int argc, _TCHAR* argv[])
...{
int i = 20;
short const & b = i;//i is not a short, so generate a short variable as a temporary variable during the convert
i = 0;
f(i);//i is not a short, so generate a short variable as a temporary variable during the convert
i = 0;
cout << i << "," << b << endl; //output : 0, 20 because b is a reference to a temporary variable
return 0;
}
对于临时变量,只能用常量的引用指向之。否则下面代码将不能编译通过
void f(short & b)
...{}
int _tmain(int argc, _TCHAR* argv[])
...{
int i = 20;
short & b = i;// can not set a non-const referenct to temporary variable
i = 0;
f(i);// can not set a non-const referenct to temporary variable
return 0;
}
...{}
int _tmain(int argc, _TCHAR* argv[])
...{
int i = 20;
short & b = i;// can not set a non-const referenct to temporary variable
i = 0;
f(i);// can not set a non-const referenct to temporary variable
return 0;
}
有人会问指针呢???指针无论是const或是non-const在这种情况下都会编译失败的