Visual C++ 2010, rvalue reference bug?
- by Sergey Shandar
Is it a bug in Visual C++ 2010 or right behaviour?
template<class T>
T f(T const &r)
{
return r;
}
template<class T>
T f(T &&r)
{
static_assert(false, "no way");
return r;
}
int main()
{
int y = 4;
f(y);
}
I thought, the function f(T &&) should never be called but it's called with T = int &. The output:
main.cpp(10): error C2338: no way
main.cpp(17) : see reference to function template instantiation 'T f<int&>(T)' being compiled
with
[
T=int &
]
Update 1 Do you know any C++x0 compiler as a reference? I've tried comeau online test-drive but could not compile r-value reference.
Update 2 Workaround (using SFINAE):
#include <boost/utility/enable_if.hpp>
#include <boost/type_traits/is_reference.hpp>
template<class T>
T f(T &r)
{
return r;
}
template<class T>
typename ::boost::disable_if< ::boost::is_reference<T>, T>::type f(T &&r)
{
static_assert(false, "no way");
return r;
}
int main()
{
int y = 4;
f(y);
// f(5); // generates "no way" error, as expected.
}
