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.

`when myCondition():` instead of `if myCondition:` is done at compile-time.

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.

FWIW, the Nim analogue of `static if` would be `when` statements.

EDIT: or any of mratsim sibling's fine choices. Nim is Choice and has many uncommon compile-time powers.