一个VS2010错误？允许绑定非const引用到右值WITHOUT EVEN警告？ [英] One VS2010 bug ? Allowing binding non-const reference to rvalue WITHOUT EVEN a warning?

问题描述

string foo() { return "hello"; }
int main() 
{
    //below should be illegal for binding a non-const (lvalue) reference to a rvalue
    string& tem  = foo();   

    //below should be the correct one as only const reference can be bind to rvalue(most important const)
    const string& constTem = foo();   
}

1. GCC是一个给予编译错误：类型 std :: 的非临时引用无效初始化 std :: string& 字符串


2. VS2008并不是太糟糕，至少它会产生编译警告：
   警告C4239： ：'initializing'：
   从 std :: string 转换为 std :: string& -const
   引用只能绑定到一个左值


3. 这里有问题 - VS2010（SP1）comples罚款没有任何
   错误或警告，WHY？ ！
   我知道VS2010中的右值引用可以用于与右值绑定，但我不使用&& 示例代码，我只是使用非常见的值引用！

1. GCC is the good one to give a compile error: invalid initialization of non-const reference of type std::string& from a temporary of type std::string
2. VS2008 is not too bad as at least it gives a compile warning: warning C4239: nonstandard extension used : 'initializing' : conversion from std::string to std::string & A non-const reference may only be bound to an lvalue
3. Here comes the problematic one - VS2010(SP1) comples fine WITHOUT any error or warning, WHY ??!! I know rvalue reference in VS2010 can be used to bind with rvalue but I am NOT using &&, instead in the demo code, I was just using non-const lvalue reference !

可以somone帮我解释VS2010的行为吗？这是一个bug！
感谢

Can somone help me explain the behavior of VS2010 here? Is it a bug !? Thanks

推荐答案

这是VS编译器的一个已知问题/功能。他们总是允许这样做，似乎没有任何推动删除扩展。

That is a known issue/feature of the VS compilers. They have always allowed that and there does not seem to be any push into removing that extension.

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