Though here be dragons: All side-effects evaluated at compile-time, are not run at compile-time! So fopen, print and all IO or OS functions should be avoided,

Though here be dragons: All side-effects evaluated at compile-time, are not run at compile-time! So fopen, print and all IO or OS functions should be avoided, or even warned. It might be useful in certain edge-cases, but in my 20 years of compile-time programming, it's almost ever a bug, not a feature.