std::ptr::write - Rust
Description: API documentation for the Rust `write` fn in crate `std`.
Keywords: rust, rustlang, rust-lang, write

# Function std::ptr::write 1.0.0 [−] [src]

    pub unsafe fn write<T>(dst: *mut T, src: T)

Overwrites a memory location with the given value without reading or dropping the old value.

# Safety

This operation is marked unsafe because it accepts a raw pointer.

It does not drop the contents of `dst`. This is safe, but it could leak allocations or resources, so care must be taken not to overwrite an object that should be dropped.

This is appropriate for initializing uninitialized memory, or overwriting memory that has previously been `read` from.

The pointer must be aligned; use `write_unaligned` if that is not the case.

# Examples

Basic usage:

    let mut x = 0;
    let y = &mut x as *mut i32;
    let z = 12;

    unsafe {
        std::ptr::write(y, z);
        assert_eq!(std::ptr::read(y), 12);
    }Run

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