Deduce template argument from std::function call signature

Question

Consider this template function:

template
ReturnT foo(const std::function& fun)
{
    return fun();
}
         


        

Answer 1

The function bar is of type bool (*)() or so, that is: a normal pre-C++11 function type. I'm not that confident in C++11, but I guess the compiler does not see the connection between bool (*)() and const std::function&, even when the first can be implicitly converted into the second for ReturnT = bool.