1.0.0[−][src]Function core::mem::zeroed
pub unsafe fn zeroed<T>() -> T
Returns the value of type T
represented by the all-zero byte-pattern.
This means that, for example, the padding byte in (u8, u16)
is not
necessarily zeroed.
There is no guarantee that an all-zero byte-pattern represents a valid value of
some type T
. For example, the all-zero byte-pattern is not a valid value
for reference types (&T
and &mut T
). Using zeroed
on such types
causes immediate undefined behavior because the Rust compiler assumes
that there always is a valid value in a variable it considers initialized.
This has the same effect as MaybeUninit::zeroed().assume_init()
.
It is useful for FFI sometimes, but should generally be avoided.
Examples
Correct usage of this function: initializing an integer with zero.
use std::mem; let x: i32 = unsafe { mem::zeroed() }; assert_eq!(0, x);Run
Incorrect usage of this function: initializing a reference with zero.
use std::mem; let _x: &i32 = unsafe { mem::zeroed() }; // Undefined behavior!Run