FileTimes::set_modified does not modify the time, but returns FileTimes

[dishmaker]

I tried this code:

https://doc.rust-lang.org/std/fs/struct.FileTimes.html#method.set_modified

let ft = FileTimes::new();

ft.set_modified(modified);

I expected to see this happen: changed modified time.

Instead, this happened: nothing, because set_modified returns Self.

Maybe #[must_use] would prevent such bugs.

Meta

Related:

• Fix set_times_nofollow for directory on windows #152083

rustc --version --verbose:

rustc 1.95.0-nightly (db3e99bba 2026-02-04)
binary: rustc
commit-hash: db3e99bbab28c6ca778b13222becdea54533d908
commit-date: 2026-02-04
host: x86_64-pc-windows-msvc
release: 1.95.0-nightly
LLVM version: 22.1.0

[eggyal]

@rustbot label -C-bug +C-enhancement +A-filesystem +D-lack-of-suggestion +E-easy -needs-triage

[yashhzd]

@rustbot claim

I'd like to work on this! Will add #[must_use] attribute to both set_modified and set_accessed methods on FileTimes to prevent accidentally discarding the returned value.