A unity build gives some of the same build time benefits as zapcc for full rebuilds, but requires more work and compromises in code structure, and also increase

A unity build gives some of the same build time benefits as zapcc for full rebuilds, but requires more work and compromises in code structure, and also increases your single-file incremental build time. If you're already using a unity build then I'd expect zapcc to not speed up full builds much if at all. I'd be interested to see if zapcc could speed up your non-unity build to be close to your unity build, without requiring the same compromises. I'd also be interested to see if zapcc would speed up single-file incremental builds in your unity build. Ultimately I can't recommend zapcc for general use as it's a fork of clang that's not being regularly rebased anymore, so it's getting out of date. That's why I wish someone would pick it up again.