# Function std::mem::copy

source ·

    pub const fn copy<T>(x: &T) -> Twhere
        T: Copy,

🔬This is a nightly-only experimental API. (`mem_copy_fn` #98262)
Expand description

Bitwise-copies a value.

This function is not magic; it is literally defined as

    pub fn copy<T: Copy>(x: &T) -> T { *x }

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It is useful when you want to pass a function pointer to a combinator, rather than defining a new closure.

Example:

    #![feature(mem_copy_fn)]
    use core::mem::copy;
    let result_from_ffi_function: Result<(), &i32> = Err(&1);
    let result_copied: Result<(), i32> = result_from_ffi_function.map_err(copy);

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