pub type NonZeroI64 = NonZero<i64>;Expand description
An integer that is known not to equal zero.
This enables some memory layout optimization.
For example, Option<NonZeroI64> is the same size as i64:
use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroI64>>(), size_of::<i64>());§Layout
NonZeroI64 is guaranteed to have the same layout and bit validity as i64
with the exception that 0 is not a valid instance.
Option<NonZeroI64> is guaranteed to be compatible with i64,
including in FFI.
Thanks to the null pointer optimization,
NonZeroI64 and Option<NonZeroI64>
are guaranteed to have the same size and alignment:
use std::num::NonZeroI64;
assert_eq!(size_of::<NonZeroI64>(), size_of::<Option<NonZeroI64>>());
assert_eq!(align_of::<NonZeroI64>(), align_of::<Option<NonZeroI64>>());Aliased Type§
struct NonZeroI64(/* private fields */);