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Description
Code
fn main() {
let mut q: &dyn Fn(_) -> _ = &|_: usize| 10_u8;
let mut q_tmp;
let x = 20_i16;
q_tmp = move |a| (a + x).clamp(0, 1);
q = &q_tmp;
}Current output
--> src/main.rs:5:22
|
5 | q_tmp = move |a| (a + x).clamp(0, 1);
| ^^^^^^^ cannot infer typeDesired output
error[E0277]: cannot add `i16` to `usize`
--> src/main.rs:5:25
|
5 | q_tmp = move |a| (a + x).clamp(0, 1);
| ^ no implementation for `usize + i16`
|
= help: the trait `Add<i16>` is not implemented for `usize`
= help: the following other types implement trait `Add<Rhs>`:
`&usize` implements `Add<usize>`
`&usize` implements `Add`
`usize` implements `Add<&usize>`
`usize` implements `Add`Rationale and extra context
This is very confusing when the contained expression is much more complicated than adding two numbers.
Other cases
Rust Version
rustc 1.86.0 (05f9846f8 2025-03-31)
binary: rustc
commit-hash: 05f9846f893b09a1be1fc8560e33fc3c815cfecb
commit-date: 2025-03-31
host: x86_64-unknown-linux-gnu
release: 1.86.0
LLVM version: 19.1.7
(also tested on the latest nightly on the playground)Anything else?
No response