Type Alias serde::lib::num::NonZeroU64

1.28.0 · source ·
pub type NonZeroU64 = NonZero<u64>;
Expand description

An integer that is known not to equal zero.

This enables some memory layout optimization. For example, Option<NonZeroU64> is the same size as u64:

use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroU64>>(), size_of::<u64>());


NonZeroU64 is guaranteed to have the same layout and bit validity as u64 with the exception that 0 is not a valid instance. Option<NonZeroU64> is guaranteed to be compatible with u64, including in FFI.

Thanks to the null pointer optimization, NonZeroU64 and Option<NonZeroU64> are guaranteed to have the same size and alignment:

use std::num::NonZeroU64;

assert_eq!(size_of::<NonZeroU64>(), size_of::<Option<NonZeroU64>>());
assert_eq!(align_of::<NonZeroU64>(), align_of::<Option<NonZeroU64>>());

Aliased Type§

struct NonZeroU64(u64);


§0: u64
🔬This is a nightly-only experimental API. (generic_nonzero)

Trait Implementations§


impl<'de> Deserialize<'de> for NonZeroU64


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

Deserialize this value from the given Serde deserializer. Read more

impl Serialize for NonZeroU64


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

Serialize this value into the given Serde serializer. Read more