Function template resolution

There are two step to resolve what function to use when calling a templated functions.

solve all arguments in parallel.
verify if there’s any inconsistency.

#include <iostream>

template <class A, class B>
void function(A a, B b) {
    std::cout << __PRETTY_FUNCTION__ << "\n";
}

int main() {
    function(10, 20); // void function(A, B) [with A = int; B = int]
    function("", 's'); // void function(A, B) [with A = const char*; B = char]
}

parameter packs are greedy and will use as much options as possible.
Eliminate specialization if one or more parameters cannot be deduced.
Fail if more than one template matches.
Fail if all templates are eliminated.