Turbofish for numeric generics in nested function call fails

[michaeljklein]

Aim

fn foo<let N: u32>() -> [u8; N] {
    [0; N]
}

fn bar<let N: u32>() -> [u8; N] {
    foo::<N>()
}

global M: u32 = 3;

fn main() {
    println(bar::<M>());
}

Expected Behavior

Program to compile and execute successfully.

Note in the workaround that using turbofish for bar in main works.

Bug

error: expected type, found numeric generic parameter N
  ┌─ /Users/michaelklein/Coding/noir/bug_from_regex/src/main.nr:6:11
  │
6 │     foo::<N>()
  │           - not a type
  │

To Reproduce

Project Impact

Blocker

Impact Context

Medium-blocker: there's a lot of code that uses numeric generics and the workarounds are fairly heavy

Workaround

Yes

Workaround Description

Phantom data that's expected to compile to () can be passed around:

struct Phantom<let N: u32> { }

fn foo<let N: u32>(x: Phantom<N>) -> [u8; N] {
    [0; N]
}

fn bar<let N: u32>(x: Phantom<N>) -> [u8; N] {
    foo(x)
}

global M: u32 = 3;

fn main() {
    let phantom: Phantom<M> = Phantom {};
    println(bar::<M>(phantom));
}

Additional Context

No response

Installation Method

Compiled from source

Nargo Version

nargo version = 0.31.0 noirc version = 0.31.0+b58a034a36dab6d17e10f2fcceab93e9073f53ed (git version hash: b58a034, is dirty: false)

NoirJS Version

No response

Would you like to submit a PR for this Issue?

None

Support Needs

No response