Although I haven't used Nim, something I miss while using rust is `static if`. You can sort of approximate / do a subset of this with #[cfg(xxx)] directives in Rust.
Alternatively you can use a `static:` code block to force compile time evaluation. Or tag a function {.compileTime.} or tag function inputs with `static` modifier.
It is possible to create a compiler or an assembler running fully in Nim macros as well:
- https://github.com/mratsim/constantine/blob/master/constanti... (all that file runs at compile-time)
You can also implement Continuation-Passing-Style transformation at compile-time: - https://github.com/nim-works/cps
Or a neural network DSL or for a self-contained example, einsum: - https://github.com/mratsim/Arraymancer/blob/master/src/array...
It's worth noting that nim async/await transformation is fully implemented as a library in macros.
EDIT: or any of mratsim sibling's fine choices. Nim is Choice and has many uncommon compile-time powers.