> I'm not sure I'd call the design "bad". At the very least it's a product of the design constraints, and I'm not sure there's an obviously better implementatio

> I'm not sure I'd call the design "bad". At the very least it's a product of the design constraints, and I'm not sure there's an obviously better implementation without sacrificing something else. It was a product of the design constraints in the 70s when memory was expensive, and compilers couldn't store a whole program in memory during compilation. The problem C++ has now is that the preprocessor operates on the raw text of a header file (which is a relic from C). This means the same header file can generate totally different source code each time its included in your program. C++ can't change that behaviour without breaking backwards compatibility. So headers get parsed over and over again "just in case" - wasting time producing excess code that just gets stripped back out again by the linker. The way C++ works doesn't make any sense now that memory is so much cheaper. Go, C#, java, rust, zig - basically every compiled language younger than C++ compiles faster than C++ because these languages don't contain C++'s design mistake. Rust doesn't share monomorphized generics across crates, but at least each crate is compiled as a single compilation unit.