Missing trailing expression in block with let else yields incorrectly spanned error message · Issue #94176 · rust-lang/rust (original) (raw)

I tried this code:

#![feature(let_else)]

pub fn test(a: Option) -> Option { let Some(_) = a else { return None; }; println!("Foo"); }

fn main() {}

I expected to see this happen: A helpful error message pointing to the end of the block.

Instead, this happened: An error message with a wrong span:

error[E0308]: mismatched types --> test.rs:4:5 | 4 | let Some(_) = a else { return None; }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected enum Option, found () | = note: expected enum Option<u32> found unit type ()

error: aborting due to previous error

For more information about this error, try rustc --explain E0308.

Meta

rustc --version --verbose:

rustc 1.60.0-nightly (b17226fcc 2022-02-18)
binary: rustc
commit-hash: b17226fcc11587fed612631be372a5b4cb89988a
commit-date: 2022-02-18
host: x86_64-unknown-linux-gnu
release: 1.60.0-nightly
LLVM version: 14.0.0

cc #87335

@rustbot labels: +T-compiler +F-let-else +requires-nightly +A-diagnostics