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generic_const_exprs suggestion to add bound interacts poorly with legacy const generics #108382
Description
Code
#![allow(incomplete_features)]
#![feature(generic_const_exprs)]
use std::arch::x86_64::*;
fn uwu<const N: i32>() {
unsafe {
let a = _mm_setzero_ps();
let b = _mm_setzero_ps();
_mm_shuffle_ps(a, b, N + 1);
}
}Current output
error: unconstrained generic constant
--> src/lib.rs:9:30
|
9 | _mm_shuffle_ps(a, b, N + 1);
| ^^^^^
|
= help: try adding a `where` bound using this expression: `where [(); _mm_shuffle_ps]:`Desired output
error: unconstrained generic constant
--> src/lib.rs:9:30
|
9 | _mm_shuffle_ps(a, b, N + 1);
| ^^^^^
|
= help: try adding a `where` bound using this expression: `where [(); N + 1]:`Rationale and extra context
No response
Other cases
No response
Anything else?
No response
Activity
IsaiahCoroama commentedon Jul 8, 2026
@rustbot claim
asquared31415 commentedon Jul 8, 2026
@IsaiahCoroama this issue probably doesn't need to be resolved because the
generic_const_exprsfeature is likely on the way to being removed. I'm uncertain if any equivalents exist forgeneric_const_args, which would be much more interesting, because those are getting active work.IsaiahCoroama commentedon Jul 8, 2026
@asquared31415 Sorry, I already made the fixes before I saw this. If the feature gets dropped, it should be easy to revert my changes (if they end up getting merged, that is).
Rollup merge of rust-lang#158981 - coroama-contrib:fix-const-generics…
Rollup merge of rust-lang#158981 - coroama-contrib:fix-const-generics…
Unrolled build for #158981