The idea of having a select number of explicitly defined implicit conversions is interesting, though, but not unheard of. (Is there not something like that in S

The idea of having a select number of explicitly defined implicit conversions is interesting, though, but not unheard of. (Is there not something like that in Scala?) However, in order to perform the simplistic algorithm that the parent comment imagines, we have to give up overloading. If you have f(A) and f(B) and an implicit conversion between A and B, and we type f(x) (where x is an A), both f(A) and f(B) could be selected. Since they might have different types, a larger expression it is a part of could be valid by picking one and not the other, but we cannot know which until we go through all possibilities. That's an exponential algorithm too.