An implementation of precompiled headers

Compilation time can be improved by precompiling interfaces so that the compiler can avoid processing unreferenced declarations. However, in C-based languages precompiling a header is difficult because a header can have several meanings depending on the context in which it is included. We present an ad hoc solution to this problem, and give the results of our precompilation strategy, which improved compile times by 25 to 65 per cent over compilation without precompiled headers.