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>());
§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>>());
Aliased Type§
struct NonZeroU32(/* private fields */);
Trait Implementations§
source§impl<'de> Deserialize<'de> for NonZeroU32
impl<'de> Deserialize<'de> for NonZeroU32
source§fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>where
D: Deserializer<'de>,
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>where
D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer. Read more