A function pointer of type bool (*)() can be converted to std::function<bool()> but is not the same type, so a conversion is needed. Before the compiler can check whether that conversion is possible it needs to deduce ReturnT as bool, but to do that it needs to already know that std::function<bool()> is a possible conversion, … Read more
The problem is that both function<int()> and function<int(int)> are constructible from the same function. This is what the constructor declaration of std::function looks like in VS2010: template<class _Fx> function(_Fx _Func, typename _Not_integral<!_Is_integral<_Fx>::value, int>::_Type = 0); Ignoring the SFINAE part, it is constructible from pretty much anything. std::/boost::function employ a technique called type erasure, to allow … Read more
In general, if you are facing a design situation that gives you a choice, use templates. I stressed the word design because I think what you need to focus on is the distinction between the use cases of std::function and templates, which are pretty different. In general, the choice of templates is just an instance … Read more