Type Alias std::num::NonZeroI128
1.34.0 · source · pub type NonZeroI128 = NonZero<i128>;
Expand description
An integer that is known not to equal zero.
This enables some memory layout optimization.
For example, Option<NonZeroI128>
is the same size as i128
:
use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroI128>>(), size_of::<i128>());
Run§Layout
NonZeroI128
is guaranteed to have the same layout and bit validity as i128
with the exception that 0
is not a valid instance.
Option<NonZeroI128>
is guaranteed to be compatible with i128
,
including in FFI.
Thanks to the null pointer optimization,
NonZeroI128
and Option<NonZeroI128>
are guaranteed to have the same size and alignment:
use std::num::NonZeroI128;
assert_eq!(size_of::<NonZeroI128>(), size_of::<Option<NonZeroI128>>());
assert_eq!(align_of::<NonZeroI128>(), align_of::<Option<NonZeroI128>>());
RunAliased Type§
struct NonZeroI128(/* private fields */);