Summary

redundant_closure lint sometimes makes incorrect suggestion in a no_std environment.

Reproducer

I tried this code:

#![no_std]
extern crate alloc;
use alloc::vec;
use alloc::vec::Vec;

fn main() {
    let _: Option<Vec<u8>>= true.then(|| vec![]);
}

I expected to see this happen:

Suggest code that compiles successfully in a no_std environment, e.g. using alloc::vec::Vec, or not linting.

Instead, this happened:

The following was suggested, which fails to compile:

#![no_std]
extern crate alloc;
use alloc::vec;
use alloc::vec::Vec;

fn main() {
    let _: Option<Vec<u8>>= true.then(std::vec::Vec::new);
}

Version

rustc 1.85.0-nightly (dd84b7d5e 2024-12-27)
binary: rustc
commit-hash: dd84b7d5eec3c20d7fcd13e6450af029d3cece9d
commit-date: 2024-12-27
host: x86_64-unknown-linux-gnu
release: 1.85.0-nightly
LLVM version: 19.1.6

Additional Labels

@rustbot label +I-suggestion-causes-error