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

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

    pub unsafe fn read<T>(src: *const T) -> T

Reads the value from `src` without moving it. This leaves the memory in `src` unchanged.

# Safety

Beyond accepting a raw pointer, this is unsafe because it semantically moves the value out of `src` without preventing further usage of `src`. If `T` is not `Copy`, then care must be taken to ensure that the value at `src` is not used before the data is overwritten again (e.g. with `write`, `write_bytes`, or `copy`). Note that `*src = foo` counts as a use because it will attempt to drop the value previously at `*src`.

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

# Examples

Basic usage:

    let x = 12;
    let y = &x as *const i32;

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

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