Here it depends on how you want to use generics. For map<T1, T2> this isn't much of an issue, since whenever you use it you'll probably be using a concrete inst

Here it depends on how you want to use generics. For map<T1, T2> this isn't much of an issue, since whenever you use it you'll probably be using a concrete instantiation. Your point still stnds though, which is why proper generics aren't something you 'tack on' to a language. You have to be prepared for it to be used pervasively. This is probably why templates are deep in the C++ StdLib; as an attempt to ensure templates really are 'part of the language'. Sadly, in this case it really expanded the language. Having a lot of code go through generics isn't necessarily an issue. The potential issue comes from having a lot of different concrete instantiations of your abstract code. That issue might be solveable by smarter compilers.