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>());Run
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);Run
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);Run
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());Run
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());Run
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());Run
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());Run
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());Run
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));Run
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) });Run
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));Run
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));Run
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.