We have a header-only C++ code base (VS 2010, Eclipse, Makefile) with about 450 files (3.6 MB). Everyday work started to become harder because of long (4 minutes) compilation times. A smaller part of it, about 20%, is templated, but others are simple classes with some template methods here and there. We are thinking about migrating the 80% to have separate .cpp and .h files.
First, I would change every templated file from .h to .hpp. That would define the scope. After that I just see tons of manual work. Maybe with some help of Visual Assist's Move implementation to source feature. At the end I am thinking in partial unity builds (compilation units of 5..20 .cpp files), but that can be done after everything.
Can you think of any better ways than manual work on about 360 files? Any speedups?