I think it's for all intents and purposes impossible to program like this in this century. Like imagine just writing x + y in C++. Are you seriously going to enumerate every declaration of operator+ in the translation unit in your head to see if it's eligible (don't forget ADL)? And then every single possible implicit conversion or promotion that could make other ones eligible? And then go through all the overload resolution rules that practically no humans have memorized (with any template instantiations that may come into play) to figure out if the declaration you wanted is actually the best match? That's before you even look at its definition...