Type Alias serde::lib::num::NonZeroI32

1.34.0 · source ·
pub type NonZeroI32 = NonZero<i32>;
Expand description

An integer that is known not to equal zero.

This enables some memory layout optimization. For example, Option<NonZeroI32> is the same size as i32:

use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroI32>>(), size_of::<i32>());

§Layout

NonZeroI32 is guaranteed to have the same layout and bit validity as i32 with the exception that 0 is not a valid instance. Option<NonZeroI32> is guaranteed to be compatible with i32, including in FFI.

Thanks to the null pointer optimization, NonZeroI32 and Option<NonZeroI32> are guaranteed to have the same size and alignment:

use std::num::NonZeroI32;

assert_eq!(size_of::<NonZeroI32>(), size_of::<Option<NonZeroI32>>());
assert_eq!(align_of::<NonZeroI32>(), align_of::<Option<NonZeroI32>>());

Aliased Type§

struct NonZeroI32(/* private fields */);

Trait Implementations§

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impl<'de> Deserialize<'de> for NonZeroI32

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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 NonZeroI32

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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