Java's generics are certainly awkward, and lots of code would look better if generics had been real from v1.0. I'm looking forward to Java's specialized generic

Java's generics are certainly awkward, and lots of code would look better if generics had been real from v1.0. I'm looking forward to Java's specialized generic impls (e.g. ArrayList<int>) that seem heavily inspired by the route C++ takes of compile-time class-instantiation. But out of curiosity what's difficult/painful about C++'s "retrofitted" generics (templates)? There's a lot to not like about templates, but as far as I know they've remained relatively unchanged and have always been just as difficult and painful (and powerful) as they are now. Are you referring to the decision to make SFINAE a de-facto way to constrain parameters?