Type Alias NonZeroU16

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1.28.0 · Source

pub type NonZeroU16 = NonZero<u16>;

Expand description

A u16 that is known not to equal zero.

This enables some memory layout optimization. For example, Option<NonZeroU16> is the same size as u16:

use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroU16>>(), size_of::<u16>());

§Layout

NonZeroU16 is guaranteed to have the same layout and bit validity as u16 with the exception that 0 is not a valid instance. Option<NonZeroU16> is guaranteed to be compatible with u16, including in FFI.

Thanks to the null pointer optimization, NonZeroU16 and Option<NonZeroU16> are guaranteed to have the same size and alignment:

use std::num::NonZeroU16;

assert_eq!(size_of::<NonZeroU16>(), size_of::<Option<NonZeroU16>>());
assert_eq!(align_of::<NonZeroU16>(), align_of::<Option<NonZeroU16>>());

Aliased Type§

struct NonZeroU16(/* private fields */);

Implementations

Source §

impl<T> NonZero<T>
where T: ZeroablePrimitive,

1.28.0 (const: 1.47.0) · Source

pub const fn new(n: T) -> Option<NonZero<T>>

Creates a non-zero if the given value is not zero.

1.28.0 (const: 1.28.0) · Source

pub const unsafe fn new_unchecked(n: T) -> NonZero<T>

Creates a non-zero without checking whether the value is non-zero. This results in undefined behavior if the value is zero.

§Safety

The value must not be zero.

Source

pub fn from_mut(n: &mut T) -> Option<&mut NonZero<T>>

🔬This is a nightly-only experimental API. (nonzero_from_mut)

Converts a reference to a non-zero mutable reference if the referenced value is not zero.

Source

pub unsafe fn from_mut_unchecked(n: &mut T) -> &mut NonZero<T>

🔬This is a nightly-only experimental API. (nonzero_from_mut)

Converts a mutable reference to a non-zero mutable reference without checking whether the referenced value is non-zero. This results in undefined behavior if the referenced value is zero.

§Safety

The referenced value must not be zero.

1.28.0 (const: 1.34.0) · Source

pub const fn get(self) -> T

Returns the contained value as a primitive type.

Source §

impl NonZero<u16>

Source

pub const fn div_ceil(self, rhs: NonZero<u16>) -> NonZero<u16>

🔬This is a nightly-only experimental API. (unsigned_nonzero_div_ceil)

Calculates the quotient of self and rhs, rounding the result towards positive infinity.

The result is guaranteed to be non-zero.

§Examples

let one = NonZero::new(1u16).unwrap();
let max = NonZero::new(u16::MAX).unwrap();
assert_eq!(one.div_ceil(max), one);

let two = NonZero::new(2u16).unwrap();
let three = NonZero::new(3u16).unwrap();
assert_eq!(three.div_ceil(two), two);

Source §

impl NonZero<u16>

1.67.0 · Source

pub const BITS: u32 = 16u32

The size of this non-zero integer type in bits.

This value is equal to u16::BITS.

§Examples

assert_eq!(NonZero::<u16>::BITS, u16::BITS);

1.70.0 · Source

pub const MIN: NonZero<u16>

The smallest value that can be represented by this non-zero integer type, 1.

§Examples

assert_eq!(NonZero::<u16>::MIN.get(), 1u16);

1.70.0 · Source

pub const MAX: NonZero<u16>

The largest value that can be represented by this non-zero integer type, equal to u16::MAX.

§Examples

assert_eq!(NonZero::<u16>::MAX.get(), u16::MAX);

1.53.0 (const: 1.53.0) · Source

pub const fn leading_zeros(self) -> u32

Returns the number of leading zeros in the binary representation of self.

On many architectures, this function can perform better than leading_zeros() on the underlying integer type, as special handling of zero can be avoided.

§Examples

Basic usage:

let n = NonZero::<u16>::new(u16::MAX)?;

assert_eq!(n.leading_zeros(), 0);

1.53.0 (const: 1.53.0) · Source

pub const fn trailing_zeros(self) -> u32

Returns the number of trailing zeros in the binary representation of self.

On many architectures, this function can perform better than trailing_zeros() on the underlying integer type, as special handling of zero can be avoided.

§Examples

Basic usage:

let n = NonZero::<u16>::new(0b0101000)?;

assert_eq!(n.trailing_zeros(), 3);

Source

pub const fn isolate_most_significant_one(self) -> NonZero<u16>

🔬This is a nightly-only experimental API. (isolate_most_least_significant_one)

Returns self with only the most significant bit set.

§Example

Basic usage:

#![feature(isolate_most_least_significant_one)]

let a = NonZero::<u16>::new(0b_01100100)?;
let b = NonZero::<u16>::new(0b_01000000)?;

assert_eq!(a.isolate_most_significant_one(), b);

Source

pub const fn isolate_least_significant_one(self) -> NonZero<u16>

🔬This is a nightly-only experimental API. (isolate_most_least_significant_one)

Returns self with only the least significant bit set.

§Example

Basic usage:

#![feature(isolate_most_least_significant_one)]

let a = NonZero::<u16>::new(0b_01100100)?;
let b = NonZero::<u16>::new(0b_00000100)?;

assert_eq!(a.isolate_least_significant_one(), b);

1.86.0 (const: 1.86.0) · Source

pub const fn count_ones(self) -> NonZero<u32>

Returns the number of ones in the binary representation of self.

§Examples

Basic usage:

let a = NonZero::<u16>::new(0b100_0000)?;
let b = NonZero::<u16>::new(0b100_0011)?;

assert_eq!(a.count_ones(), NonZero::new(1)?);
assert_eq!(b.count_ones(), NonZero::new(3)?);

Source

pub const fn rotate_left(self, n: u32) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_bitwise)

Shifts the bits to the left by a specified amount, n, wrapping the truncated bits to the end of the resulting integer.

Please note this isn’t the same operation as the << shifting operator!

§Examples

Basic usage:

#![feature(nonzero_bitwise)]
let n = NonZero::new(0xa003u16)?;
let m = NonZero::new(0x3a)?;

assert_eq!(n.rotate_left(4), m);

Source

pub const fn rotate_right(self, n: u32) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_bitwise)

Shifts the bits to the right by a specified amount, n, wrapping the truncated bits to the beginning of the resulting integer.

Please note this isn’t the same operation as the >> shifting operator!

§Examples

Basic usage:

#![feature(nonzero_bitwise)]
let n = NonZero::new(0x3au16)?;
let m = NonZero::new(0xa003)?;

assert_eq!(n.rotate_right(4), m);

Source

pub const fn swap_bytes(self) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_bitwise)

Reverses the byte order of the integer.

§Examples

Basic usage:

#![feature(nonzero_bitwise)]
let n = NonZero::new(0x1234u16)?;
let m = n.swap_bytes();

assert_eq!(m, NonZero::new(0x3412)?);

Source

pub const fn reverse_bits(self) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_bitwise)

Reverses the order of bits in the integer. The least significant bit becomes the most significant bit, second least-significant bit becomes second most-significant bit, etc.

§Examples

Basic usage:

#![feature(nonzero_bitwise)]
let n = NonZero::new(0x1234u16)?;
let m = n.reverse_bits();

assert_eq!(m, NonZero::new(0x2c48)?);

Source

pub const fn from_be(x: NonZero<u16>) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_bitwise)

Converts an integer from big endian to the target’s endianness.

On big endian this is a no-op. On little endian the bytes are swapped.

§Examples

Basic usage:

#![feature(nonzero_bitwise)]
use std::num::NonZeroU16;
let n = NonZero::new(0x1Au16)?;

if cfg!(target_endian = "big") {
    assert_eq!(NonZeroU16::from_be(n), n)
} else {
    assert_eq!(NonZeroU16::from_be(n), n.swap_bytes())
}

Source

pub const fn from_le(x: NonZero<u16>) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_bitwise)

Converts an integer from little endian to the target’s endianness.

On little endian this is a no-op. On big endian the bytes are swapped.

§Examples

Basic usage:

#![feature(nonzero_bitwise)]
use std::num::NonZeroU16;
let n = NonZero::new(0x1Au16)?;

if cfg!(target_endian = "little") {
    assert_eq!(NonZeroU16::from_le(n), n)
} else {
    assert_eq!(NonZeroU16::from_le(n), n.swap_bytes())
}

Source

pub const fn to_be(self) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_bitwise)

Converts self to big endian from the target’s endianness.

On big endian this is a no-op. On little endian the bytes are swapped.

§Examples

Basic usage:

#![feature(nonzero_bitwise)]
let n = NonZero::new(0x1Au16)?;

if cfg!(target_endian = "big") {
    assert_eq!(n.to_be(), n)
} else {
    assert_eq!(n.to_be(), n.swap_bytes())
}

Source

pub const fn to_le(self) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_bitwise)

Converts self to little endian from the target’s endianness.

On little endian this is a no-op. On big endian the bytes are swapped.

§Examples

Basic usage:

#![feature(nonzero_bitwise)]
let n = NonZero::new(0x1Au16)?;

if cfg!(target_endian = "little") {
    assert_eq!(n.to_le(), n)
} else {
    assert_eq!(n.to_le(), n.swap_bytes())
}

1.64.0 (const: 1.64.0) · Source

pub const fn checked_add(self, other: u16) -> Option<NonZero<u16>>

Adds an unsigned integer to a non-zero value. Checks for overflow and returns None on overflow. As a consequence, the result cannot wrap to zero.

§Examples

let one = NonZero::new(1u16)?;
let two = NonZero::new(2u16)?;
let max = NonZero::new(u16::MAX)?;

assert_eq!(Some(two), one.checked_add(1));
assert_eq!(None, max.checked_add(1));

1.64.0 (const: 1.64.0) · Source

pub const fn saturating_add(self, other: u16) -> NonZero<u16>

Adds an unsigned integer to a non-zero value. Return NonZero::<u16>::MAX on overflow.

§Examples

let one = NonZero::new(1u16)?;
let two = NonZero::new(2u16)?;
let max = NonZero::new(u16::MAX)?;

assert_eq!(two, one.saturating_add(1));
assert_eq!(max, max.saturating_add(1));

Source

pub const unsafe fn unchecked_add(self, other: u16) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_ops)

Adds an unsigned integer to a non-zero value, assuming overflow cannot occur. Overflow is unchecked, and it is undefined behavior to overflow even if the result would wrap to a non-zero value. The behavior is undefined as soon as self + rhs > u16::MAX.

§Examples

#![feature(nonzero_ops)]

let one = NonZero::new(1u16)?;
let two = NonZero::new(2u16)?;

assert_eq!(two, unsafe { one.unchecked_add(1) });

1.64.0 (const: 1.64.0) · Source

pub const fn checked_next_power_of_two(self) -> Option<NonZero<u16>>

Returns the smallest power of two greater than or equal to self. Checks for overflow and returns None if the next power of two is greater than the type’s maximum value. As a consequence, the result cannot wrap to zero.

§Examples

let two = NonZero::new(2u16)?;
let three = NonZero::new(3u16)?;
let four = NonZero::new(4u16)?;
let max = NonZero::new(u16::MAX)?;

assert_eq!(Some(two), two.checked_next_power_of_two() );
assert_eq!(Some(four), three.checked_next_power_of_two() );
assert_eq!(None, max.checked_next_power_of_two() );

1.67.0 (const: 1.67.0) · Source

pub const fn ilog2(self) -> u32

Returns the base 2 logarithm of the number, rounded down.

This is the same operation as u16::ilog2, except that it has no failure cases to worry about since this value can never be zero.

§Examples

assert_eq!(NonZero::new(7u16)?.ilog2(), 2);
assert_eq!(NonZero::new(8u16)?.ilog2(), 3);
assert_eq!(NonZero::new(9u16)?.ilog2(), 3);

1.67.0 (const: 1.67.0) · Source

pub const fn ilog10(self) -> u32

Returns the base 10 logarithm of the number, rounded down.

This is the same operation as u16::ilog10, except that it has no failure cases to worry about since this value can never be zero.

§Examples

assert_eq!(NonZero::new(99u16)?.ilog10(), 1);
assert_eq!(NonZero::new(100u16)?.ilog10(), 2);
assert_eq!(NonZero::new(101u16)?.ilog10(), 2);

1.85.0 (const: 1.85.0) · Source

pub const fn midpoint(self, rhs: NonZero<u16>) -> NonZero<u16>

Calculates the middle point of self and rhs.

midpoint(a, b) is (a + b) >> 1 as if it were performed in a sufficiently-large signed integral type. This implies that the result is always rounded towards negative infinity and that no overflow will ever occur.

§Examples

let one = NonZero::new(1u16)?;
let two = NonZero::new(2u16)?;
let four = NonZero::new(4u16)?;

assert_eq!(one.midpoint(four), two);
assert_eq!(four.midpoint(one), two);

1.59.0 (const: 1.59.0) · Source

pub const fn is_power_of_two(self) -> bool

Returns true if and only if self == (1 << k) for some k.

On many architectures, this function can perform better than is_power_of_two() on the underlying integer type, as special handling of zero can be avoided.

§Examples

Basic usage:

let eight = NonZero::new(8u16)?;
assert!(eight.is_power_of_two());
let ten = NonZero::new(10u16)?;
assert!(!ten.is_power_of_two());

1.84.0 (const: 1.84.0) · Source

pub const fn isqrt(self) -> NonZero<u16>

Returns the square root of the number, rounded down.

§Examples

Basic usage:

let ten = NonZero::new(10u16)?;
let three = NonZero::new(3u16)?;

assert_eq!(ten.isqrt(), three);

1.87.0 (const: 1.87.0) · Source

pub const fn cast_signed(self) -> NonZero<i16>

Returns the bit pattern of self reinterpreted as a signed integer of the same size.

§Examples

Basic usage:


let n = NonZero::<u16>::MAX;

assert_eq!(n.cast_signed(), NonZero::new(-1i16).unwrap());

1.64.0 (const: 1.64.0) · Source

pub const fn checked_mul(self, other: NonZero<u16>) -> Option<NonZero<u16>>

Multiplies two non-zero integers together. Checks for overflow and returns None on overflow. As a consequence, the result cannot wrap to zero.

§Examples

let two = NonZero::new(2u16)?;
let four = NonZero::new(4u16)?;
let max = NonZero::new(u16::MAX)?;

assert_eq!(Some(four), two.checked_mul(two));
assert_eq!(None, max.checked_mul(two));

1.64.0 (const: 1.64.0) · Source

pub const fn saturating_mul(self, other: NonZero<u16>) -> NonZero<u16>

Multiplies two non-zero integers together. Return NonZero::<u16>::MAX on overflow.

§Examples

let two = NonZero::new(2u16)?;
let four = NonZero::new(4u16)?;
let max = NonZero::new(u16::MAX)?;

assert_eq!(four, two.saturating_mul(two));
assert_eq!(max, four.saturating_mul(max));

Source

pub const unsafe fn unchecked_mul(self, other: NonZero<u16>) -> NonZero<u16>

🔬This is a nightly-only experimental API. (nonzero_ops)

Multiplies two non-zero integers together, assuming overflow cannot occur. Overflow is unchecked, and it is undefined behavior to overflow even if the result would wrap to a non-zero value. The behavior is undefined as soon as self * rhs > u16::MAX.

§Examples

#![feature(nonzero_ops)]

let two = NonZero::new(2u16)?;
let four = NonZero::new(4u16)?;

assert_eq!(four, unsafe { two.unchecked_mul(two) });

1.64.0 (const: 1.64.0) · Source

pub const fn checked_pow(self, other: u32) -> Option<NonZero<u16>>

Raises non-zero value to an integer power. Checks for overflow and returns None on overflow. As a consequence, the result cannot wrap to zero.

§Examples

let three = NonZero::new(3u16)?;
let twenty_seven = NonZero::new(27u16)?;
let half_max = NonZero::new(u16::MAX / 2)?;

assert_eq!(Some(twenty_seven), three.checked_pow(3));
assert_eq!(None, half_max.checked_pow(3));

1.64.0 (const: 1.64.0) · Source

pub const fn saturating_pow(self, other: u32) -> NonZero<u16>

Raise non-zero value to an integer power. Return NonZero::<u16>::MAX on overflow.

§Examples

let three = NonZero::new(3u16)?;
let twenty_seven = NonZero::new(27u16)?;
let max = NonZero::new(u16::MAX)?;

assert_eq!(twenty_seven, three.saturating_pow(3));
assert_eq!(max, max.saturating_pow(3));