Static rustc_lint::drop_forget_useless::FORGET_COPY

pub static FORGET_COPY: &Lint

The forget_copy lint checks for calls to std::mem::forget with a value that derives the Copy trait.

Example

let x: i32 = 42; // i32 implements Copy
std::mem::forget(x); // A copy of x is passed to the function, leaving the
                     // original unaffected

{{produces}}

Explanation

Calling std::mem::forget does nothing for types that implement Copy since the value will be copied and moved into the function on invocation.

An alternative, but also valid, explanation is that Copy types do not implement the Drop trait, which means they have no destructors. Without a destructor, there is nothing for std::mem::forget to ignore.