I found that gcc works mostly alright on swap for compiling C++. I assume that data structures for template instantiations are never really deallocated, and it

I found that gcc works mostly alright on swap for compiling C++. I assume that data structures for template instantiations are never really deallocated, and it often falls into category 2 of your deacription. And then compilation eventually finishes and the allocated memory is released on process termination.