Assume the following situation:
Type A and type B, B can be implicitly converted to A but the opposite is untrue.
I have a function
template<class T>
void do_stuff(T a, T b);
I want to call said function as such:
do_stuff(A{}, B{});
The problem here is that the compiler can't deduce the type and instead says:
template argument deduction/substitution failed
I can call my function like this:
do_stuff<A>(A{}, B{});
But this is more annoying for the user.
Alternatively I can do something like this:
template<class T, class M>
void do_stuff(T a, M b);
But then b goes on its merry way to be of type B (with the prior invocation).
Ideally I would like something like:
template<class T, class M = T>
void do_stuff(T a, M b);
Or:
template<class T@INSERT MAGIC SO THAT T IS DEDUCED AS BEING THE TYPE OF ARGUMENT NR 1@>
void do_stuff(T a, T b);
Is such a thing possible ?