Type Alias std::num::NonZeroU32
1.28.0 · source · pub type NonZeroU32 = NonZero<u32>;
Expand description
An integer that is known not to equal zero.
This enables some memory layout optimization.
For example, Option<NonZeroU32>
is the same size as u32
:
use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroU32>>(), size_of::<u32>());
Run§Layout
NonZeroU32
is guaranteed to have the same layout and bit validity as u32
with the exception that 0
is not a valid instance.
Option<NonZeroU32>
is guaranteed to be compatible with u32
,
including in FFI.
Thanks to the null pointer optimization,
NonZeroU32
and Option<NonZeroU32>
are guaranteed to have the same size and alignment:
use std::num::NonZeroU32;
assert_eq!(size_of::<NonZeroU32>(), size_of::<Option<NonZeroU32>>());
assert_eq!(align_of::<NonZeroU32>(), align_of::<Option<NonZeroU32>>());
RunAliased Type§
struct NonZeroU32(/* private fields */);