This kind of thing is one of the reasons I'm really interested in languages that support multi-stage programming. I've played around with Terra and lately I've

This kind of thing is one of the reasons I'm really interested in languages that support multi-stage programming. I've played around with Terra and lately I've read many good things about Zig, because they both let you run code at compile-time. Things like dependency-injection could be zero-cost if done at an early compilation stage, so the compiler has a chance to optimise the code with the correct dependency already in place.