Reference to rvalue in C++03

[rollie]

This seems to me that it should not work, but in VC++ 2008 express it is compiling and running happily. Shouldn't the compiler be complaining about assinging a reference to an rvalue? I'm a bit out of practice these days, so maybe forgetting something here.

class foo
{
public:
};

foo bar()
{
  return foo();
}

int main()
{
  foo & myRef = bar();

  return 0;
}

[Moschops]

g++ says: "error: invalid initialization of non-const reference of type ‘foo&’ from a temporary of type ‘foo’"

clang++ says: " error: non-const lvalue reference to type 'class foo' cannot bind to a temporary of type 'class foo'"

Change foo & myRef = bar(); to const foo & myRef = bar(); and they are happy.

[Cubbi]

This is a long-standing bug non-standard language extension of Visual Studio. Like "void main()"

At /W4, Visual Studio 2010 says

warning C4239: nonstandard extension used : 'initializing' : conversion from 'foo' to 'foo &'
A non-const reference may only be bound to an lvalue

(note that this remains illegal in C++11)

[rollie]

Glad to hear - not crazy :) Thanks guys.