Clippy lints / Restriction
Clippy lint · Restriction · checked with Clippy 0.1.99
clippy::mem_forget: Checks for usage of std::mem::forget(t) where t is Drop or has a field that implements Drop
What it meansChecks for usage of std::mem::forget(t) where t is Drop or has a field that implements Drop. It is in the restriction group and off by default.
Does it matter?
std::mem::forget(t) prevents t from running its destructor, possibly causing leaks. It is not possible to detect all means of creating leaks, but it may be desirable to prohibit the simple ones.
Lints that forbid language features for specific codebases (no unwrap, no indexing...). Off by default; pick them one by one, never the whole group.
How to fix it
Clippy does not fix this one automatically. Change the code by hand:
Flagged
mem::forget(Rc::new(55))
Turn it off, or on
It is off by default. To use it, set it to warn or deny:
Whole crate (Cargo.toml)
[lints.clippy]
mem_forget = "warn"In code
#![warn(clippy::mem_forget)]One run
cargo clippy -- -W clippy::mem-forgetThe [lints] table needs Rust 1.74 or newer. In a workspace, put it under [workspace.lints.clippy] and add [lints] workspace = true to each member.
Clippy's own documentation
What it does
Checks for usage of std::mem::forget(t) where t is
Drop or has a field that implements Drop.
Why restrict this?
std::mem::forget(t) prevents t from running its destructor, possibly causing leaks.
It is not possible to detect all means of creating leaks, but it may be desirable to
prohibit the simple ones.
Example
mem::forget(Rc::new(55))
From the Clippy lint list (0.1.99), part of the Rust project, MIT or Apache-2.0. Official entry.
Related lints
- unwrap_usedChecks for .unwrap() or .unwrap_err() calls on Results and .unwrap() call on Options
- module_name_repetitionsDetects public item names that are prefixed or suffixed by the containing public module’s name
- expect_usedChecks for .expect() or .expect_err() calls on Results and .expect() call on Options
- lossy_float_literalliteral cannot be represented as the underlying type without loss of precision
- map_err_ignore`map_err(|_|...` wildcard pattern discards the original error
- map_with_unused_argument_over_rangesmap of a closure that does not depend on its parameter over a range
- min_ident_charsChecks for identifiers which consist of a single character (or fewer than the configured threshold). Note: This lint can be very noisy when enabled; it may be desirable to only enable it temporarily
- missing_assert_messageChecks assertions without a custom panic message
- missing_asserts_for_indexingindexing into a slice multiple times without an `assert`
All 847 Clippy lints · Rust compiler errors · Cargo.toml checker
Up next
Related lintclippy::unwrap_usedChecks for .unwrap() or .unwrap_err() calls on Results and .unwrap() call on OptionsRead it next →Did this answer your question?