Struct core::num::NonZeroI8 1.34.0[−][src]
#[repr(transparent)]pub struct NonZeroI8(_);Expand description
An integer that is known not to equal zero.
This enables some memory layout optimization.
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>());Implementations
Creates a non-zero without checking whether the value is non-zero. This results in undefined behaviour if the value is zero.
Safety
The value must not be zero.
Creates a non-zero if the given value is not zero.
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 = std::num::NonZeroI8::new(-1i8).unwrap();
assert_eq!(n.leading_zeros(), 0);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 = std::num::NonZeroI8::new(0b0101000).unwrap();
assert_eq!(n.trailing_zeros(), 3);Checked absolute value.
Check for overflow and returns None if
self == i8::MIN.
The result cannot be zero.
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());Computes the absolute value of self,
with overflow information, see
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());Saturating absolute value, see
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());Wrapping absolute value, see
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());Computes the absolute value of self without any wrapping or panicking.
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());Multiply two non-zero integers together.
Check for overflow and return None on overflow.
As a consequence, the result cannot wrap to zero.
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));Multiply two non-zero integers together,
assuming overflow cannot occur.
Overflow is unchecked, and it is undefined behaviour to overflow
even if the result would wrap to a non-zero value.
The behaviour is undefined as soon as
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) });Raise non-zero value to an integer power.
Check for overflow and return None on overflow.
As a consequence, the result cannot wrap to zero.
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));Raise non-zero value to an integer power.
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));Trait Implementations
Performs the |= operation. Read more
Performs the |= operation. Read more
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Attempts to convert NonZeroI128 to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroI16 to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroI32 to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroI64 to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroU128 to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroU16 to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroU32 to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroU64 to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroUsize to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.