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 */);