Struct core::num::NonZeroI81.34.0[−][src]

#[repr(transparent)]
pub struct NonZeroI8(_);

Expand description

已知不等于零的整数。

这样可以进行一些内存布局优化。 For example, Option<NonZeroI8> is the same size as i8:

use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroI8>>(), size_of::<i8>());

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Implementations

impl NonZeroI8

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pub const unsafe fn new_unchecked(n: i8) -> Self

1.34.0 (const: 1.34.0)[src]

创建一个非零值而不检查该值是否为非零值。如果该值为零，这将导致未定义的行为。

Safety

该值不能为零。

pub const fn new(n: i8) -> Option<Self>

1.34.0 (const: 1.47.0)[src]

如果给定值不为零，则创建一个非零值。

pub const fn get(self) -> i8

1.34.0 (const: 1.34.0)[src]

以原始类型返回该值。

impl NonZeroI8

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pub const fn leading_zeros(self) -> u32

1.53.0 (const: 1.53.0)[src]

返回 self 二进制表示形式中前导零的数目。

在许多体系结构上，此函数可以在基础整数类型上比 leading_zeros() 更好地执行，因为可以避免对零的特殊处理。

Examples

基本用法:

let n = std::num::NonZeroI8::new(-1i8).unwrap();

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

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pub const fn trailing_zeros(self) -> u32

1.53.0 (const: 1.53.0)[src]

返回 self 二进制表示形式中的尾随零数。

在许多体系结构上，此函数可以在基础整数类型上比 trailing_zeros() 更好地执行，因为可以避免对零的特殊处理。

Examples

基本用法:

let n = std::num::NonZeroI8::new(0b0101000).unwrap();

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

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impl NonZeroI8

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pub const fn abs(self) -> NonZeroI8

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

计算 self 的绝对值。 See i8::abs 有关溢出行为的文档。

Example

#![feature(nonzero_ops)]

let pos = NonZeroI8::new(1)?;
let neg = NonZeroI8::new(-1)?;

assert_eq!(pos, pos.abs());
assert_eq!(pos, neg.abs());

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pub const fn checked_abs(self) -> Option<NonZeroI8>

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

检查的绝对值。检查溢出并返回 None 如果 self == i8::MIN. 结果不能为零。

Example

#![feature(nonzero_ops)]

let pos = NonZeroI8::new(1)?;
let neg = NonZeroI8::new(-1)?;
let min = NonZeroI8::new(i8::MIN)?;

assert_eq!(Some(pos), neg.checked_abs());
assert_eq!(None, min.checked_abs());

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pub const fn overflowing_abs(self) -> (NonZeroI8, bool)

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

计算 self 的绝对值，带有溢出信息，请参见

i8::overflowing_abs.

Example

#![feature(nonzero_ops)]

let pos = NonZeroI8::new(1)?;
let neg = NonZeroI8::new(-1)?;
let min = NonZeroI8::new(i8::MIN)?;

assert_eq!((pos, false), pos.overflowing_abs());
assert_eq!((pos, false), neg.overflowing_abs());
assert_eq!((min, true), min.overflowing_abs());

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pub const fn saturating_abs(self) -> NonZeroI8

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

饱和绝对值，请参见 i8::saturating_abs.

Example

#![feature(nonzero_ops)]

let pos = NonZeroI8::new(1)?;
let neg = NonZeroI8::new(-1)?;
let min = NonZeroI8::new(i8::MIN)?;
let min_plus = NonZeroI8::new(i8::MIN + 1)?;
let max = NonZeroI8::new(i8::MAX)?;

assert_eq!(pos, pos.saturating_abs());
assert_eq!(pos, neg.saturating_abs());
assert_eq!(max, min.saturating_abs());
assert_eq!(max, min_plus.saturating_abs());

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pub const fn wrapping_abs(self) -> NonZeroI8

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

包装绝对值，请参见 i8::wrapping_abs.

Example

#![feature(nonzero_ops)]

let pos = NonZeroI8::new(1)?;
let neg = NonZeroI8::new(-1)?;
let min = NonZeroI8::new(i8::MIN)?;
let max = NonZeroI8::new(i8::MAX)?;

assert_eq!(pos, pos.wrapping_abs());
assert_eq!(pos, neg.wrapping_abs());
assert_eq!(min, min.wrapping_abs());

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pub const fn unsigned_abs(self) -> NonZeroU8

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

在没有任何包装或 panicking 的情况下计算 self 的绝对值。

Example

#![feature(nonzero_ops)]


let u_pos = NonZeroU8::new(1)?;
let i_pos = NonZeroI8::new(1)?;
let i_neg = NonZeroI8::new(-1)?;
let i_min = NonZeroI8::new(i8::MIN)?;
let u_max = NonZeroU8::new(u8::MAX / 2 + 1)?;

assert_eq!(u_pos, i_pos.unsigned_abs());
assert_eq!(u_pos, i_neg.unsigned_abs());
assert_eq!(u_max, i_min.unsigned_abs());

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impl NonZeroI8

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pub const fn checked_mul(self, other: NonZeroI8) -> Option<NonZeroI8>

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

将两个非零整数相乘。检查溢出并在溢出时返回 None。因此，结果不能归零。

Examples

#![feature(nonzero_ops)]

let two = NonZeroI8::new(2)?;
let four = NonZeroI8::new(4)?;
let max = NonZeroI8::new(i8::MAX)?;

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

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pub const fn saturating_mul(self, other: NonZeroI8) -> NonZeroI8

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

将两个非零整数相乘。 Return i8::MAX on overflow.

Examples

#![feature(nonzero_ops)]

let two = NonZeroI8::new(2)?;
let four = NonZeroI8::new(4)?;
let max = NonZeroI8::new(i8::MAX)?;

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

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pub unsafe fn unchecked_mul(self, other: NonZeroI8) -> NonZeroI8

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

假设不会发生溢出，将两个非零整数相乘。溢出未检查，如果结果将换行为非零值，则溢出 *even 是未定义的行为 *。

该行为是未定义的

self * rhs > i8::MAX, or self * rhs < i8::MIN.

Examples

#![feature(nonzero_ops)]

let two = NonZeroI8::new(2)?;
let four = NonZeroI8::new(4)?;

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

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pub const fn checked_pow(self, other: u32) -> Option<NonZeroI8>

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

将非零值提高到整数幂。检查溢出并在溢出时返回 None。因此，结果不能归零。

Examples

#![feature(nonzero_ops)]

let three = NonZeroI8::new(3)?;
let twenty_seven = NonZeroI8::new(27)?;
let half_max = NonZeroI8::new(i8::MAX / 2)?;

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

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pub const fn saturating_pow(self, other: u32) -> NonZeroI8

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🔬 This is a nightly-only experimental API. (nonzero_ops #84186)

将非零值提高到整数幂。 Return i8::MIN or i8::MAX on overflow.

Examples

#![feature(nonzero_ops)]

let three = NonZeroI8::new(3)?;
let twenty_seven = NonZeroI8::new(27)?;
let max = NonZeroI8::new(i8::MAX)?;

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