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 */);