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## NonZeroI16

# Type Alias NonZeroI16

1.34.0 · Source

    pub type NonZeroI16 = NonZero<i16>;

Expand description

An `i16` that is known not to equal zero.

This enables some memory layout optimization. For example, `Option<NonZeroI16>` is the same size as `i16`:

    assert_eq!(size_of::<Option<core::num::NonZeroI16>>(), size_of::<i16>());

## §Layout

`NonZeroI16` is guaranteed to have the same layout and bit validity as `i16` with the exception that `0` is not a valid instance. `Option<NonZeroI16>` is guaranteed to be compatible with `i16`, including in FFI.

Thanks to the null pointer optimization, `NonZeroI16` and `Option<NonZeroI16>` are guaranteed to have the same size and alignment:

    use std::num::NonZeroI16;

    assert_eq!(size_of::<NonZeroI16>(), size_of::<Option<NonZeroI16>>());
    assert_eq!(align_of::<NonZeroI16>(), align_of::<Option<NonZeroI16>>());

## §Compile-time creation

Since both `Option::unwrap()` and `Option::expect()` are `const`, it is possible to define a new `NonZeroI16` at compile time via:

    use std::num::NonZeroI16;

    const TEN: NonZeroI16 = NonZeroI16::new(10).expect("ten is non-zero");

## Aliased Type§

    pub struct NonZeroI16(/* private fields */);