Type Alias serde::lib::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>());

§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(u32);

Fields§

§0: u32
🔬This is a nightly-only experimental API. (generic_nonzero)

Trait Implementations§

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impl<'de> Deserialize<'de> for NonZeroU32

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fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer. Read more
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impl Serialize for NonZeroU32

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fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where S: Serializer,

Serialize this value into the given Serde serializer. Read more