pub type NonZeroI8 = NonZero<i8>;Expand description
An integer that is known not to equal zero.
This enables some memory layout optimization.
For example, Option<NonZeroI8> is the same size as i8:
use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroI8>>(), size_of::<i8>());Run§Layout
NonZeroI8 is guaranteed to have the same layout and bit validity as i8
with the exception that 0 is not a valid instance.
Option<NonZeroI8> is guaranteed to be compatible with i8,
including in FFI.
Thanks to the null pointer optimization,
NonZeroI8 and Option<NonZeroI8>
are guaranteed to have the same size and alignment:
use std::num::NonZeroI8;
assert_eq!(size_of::<NonZeroI8>(), size_of::<Option<NonZeroI8>>());
assert_eq!(align_of::<NonZeroI8>(), align_of::<Option<NonZeroI8>>());RunAliased Type§
struct NonZeroI8(/* private fields */);