Struct scale_info::prelude::num::NonZeroUsize
1.28.0 · source · [−]#[repr(transparent)]pub struct NonZeroUsize(_);Expand description
An integer that is known not to equal zero.
This enables some memory layout optimization.
For example, Option<NonZeroUsize> is the same size as usize:
use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroUsize>>(), size_of::<usize>());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::NonZeroUsize::new(usize::MAX).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::NonZeroUsize::new(0b0101000).unwrap();
assert_eq!(n.trailing_zeros(), 3);🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)Add an unsigned integer to a non-zero value.
Check for overflow and return None on overflow
As a consequence, the result cannot wrap to zero.
Examples
#![feature(nonzero_ops)]
let one = NonZeroUsize::new(1)?;
let two = NonZeroUsize::new(2)?;
let max = NonZeroUsize::new(usize::MAX)?;
assert_eq!(Some(two), one.checked_add(1));
assert_eq!(None, max.checked_add(1));🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)Add an unsigned integer to a non-zero value.
Return usize::MAX on overflow.
Examples
#![feature(nonzero_ops)]
let one = NonZeroUsize::new(1)?;
let two = NonZeroUsize::new(2)?;
let max = NonZeroUsize::new(usize::MAX)?;
assert_eq!(two, one.saturating_add(1));
assert_eq!(max, max.saturating_add(1));🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)Add an unsigned integer to a non-zero value,
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 > usize::MAX.
Examples
#![feature(nonzero_ops)]
let one = NonZeroUsize::new(1)?;
let two = NonZeroUsize::new(2)?;
assert_eq!(two, unsafe { one.unchecked_add(1) });🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)Returns the smallest power of two greater than or equal to n.
Check for overflow and return 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
#![feature(nonzero_ops)]
let two = NonZeroUsize::new(2)?;
let three = NonZeroUsize::new(3)?;
let four = NonZeroUsize::new(4)?;
let max = NonZeroUsize::new(usize::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() );🔬 This is a nightly-only experimental API. (int_log)
int_log)Returns the base 2 logarithm of the number, rounded down.
This is the same operation as
usize::log2,
except that it has no failure cases to worry about
since this value can never be zero.
Examples
#![feature(int_log)]
assert_eq!(NonZeroUsize::new(7).unwrap().log2(), 2);
assert_eq!(NonZeroUsize::new(8).unwrap().log2(), 3);
assert_eq!(NonZeroUsize::new(9).unwrap().log2(), 3);🔬 This is a nightly-only experimental API. (int_log)
int_log)Returns the base 10 logarithm of the number, rounded down.
This is the same operation as
usize::log10,
except that it has no failure cases to worry about
since this value can never be zero.
Examples
#![feature(int_log)]
assert_eq!(NonZeroUsize::new(99).unwrap().log10(), 1);
assert_eq!(NonZeroUsize::new(100).unwrap().log10(), 2);
assert_eq!(NonZeroUsize::new(101).unwrap().log10(), 2);🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)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 = NonZeroUsize::new(2)?;
let four = NonZeroUsize::new(4)?;
let max = NonZeroUsize::new(usize::MAX)?;
assert_eq!(Some(four), two.checked_mul(two));
assert_eq!(None, max.checked_mul(two));🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)Multiply two non-zero integers together.
Return usize::MAX on overflow.
Examples
#![feature(nonzero_ops)]
let two = NonZeroUsize::new(2)?;
let four = NonZeroUsize::new(4)?;
let max = NonZeroUsize::new(usize::MAX)?;
assert_eq!(four, two.saturating_mul(two));
assert_eq!(max, four.saturating_mul(max));🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)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 > usize::MAX.
Examples
#![feature(nonzero_ops)]
let two = NonZeroUsize::new(2)?;
let four = NonZeroUsize::new(4)?;
assert_eq!(four, unsafe { two.unchecked_mul(two) });🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)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 = NonZeroUsize::new(3)?;
let twenty_seven = NonZeroUsize::new(27)?;
let half_max = NonZeroUsize::new(usize::MAX / 2)?;
assert_eq!(Some(twenty_seven), three.checked_pow(3));
assert_eq!(None, half_max.checked_pow(3));🔬 This is a nightly-only experimental API. (nonzero_ops)
nonzero_ops)Raise non-zero value to an integer power.
Return usize::MAX on overflow.
Examples
#![feature(nonzero_ops)]
let three = NonZeroUsize::new(3)?;
let twenty_seven = NonZeroUsize::new(27)?;
let max = NonZeroUsize::new(usize::MAX)?;
assert_eq!(twenty_seven, three.saturating_pow(3));
assert_eq!(max, max.saturating_pow(3));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 = std::num::NonZeroUsize::new(8).unwrap();
assert!(eight.is_power_of_two());
let ten = std::num::NonZeroUsize::new(10).unwrap();
assert!(!ten.is_power_of_two());Trait Implementations
type Output = NonZeroUsize
type Output = NonZeroUsize
The resulting type after applying the | operator.
pub fn bitor(self, rhs: NonZeroUsize) -> <usize as BitOr<NonZeroUsize>>::Output
pub fn bitor(self, rhs: NonZeroUsize) -> <usize as BitOr<NonZeroUsize>>::Output
Performs the | operation. Read more
type Output = NonZeroUsize
type Output = NonZeroUsize
The resulting type after applying the | operator.
pub fn bitor(
self,
rhs: NonZeroUsize
) -> <NonZeroUsize as BitOr<NonZeroUsize>>::Output
pub fn bitor(
self,
rhs: NonZeroUsize
) -> <NonZeroUsize as BitOr<NonZeroUsize>>::Output
Performs the | operation. Read more
Performs the |= operation. Read more
Performs the |= operation. Read more
pub fn deserialize<D>(
deserializer: D
) -> Result<NonZeroUsize, <D as Deserializer<'de>>::Error> where
D: Deserializer<'de>,
pub fn deserialize<D>(
deserializer: D
) -> Result<NonZeroUsize, <D as Deserializer<'de>>::Error> where
D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer. Read more
Converts NonZeroU16 to NonZeroUsize losslessly.
Converts NonZeroU8 to NonZeroUsize losslessly.
type Err = ParseIntError
type Err = ParseIntError
The associated error which can be returned from parsing.
Parses a string s to return a value of this type. Read more
This method tests for self and other values to be equal, and is used
by ==. Read more
This method tests for !=.
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
pub fn serialize<S>(
&self,
serializer: S
) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error> where
S: Serializer,
pub fn serialize<S>(
&self,
serializer: S
) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error> where
S: Serializer,
Serialize this value into the given Serde serializer. Read more
pub fn try_from(
value: NonZeroI128
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI128>>::Error>
pub fn try_from(
value: NonZeroI128
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI128>>::Error>
Attempts to convert NonZeroI128 to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroI16
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI16>>::Error>
pub fn try_from(
value: NonZeroI16
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI16>>::Error>
Attempts to convert NonZeroI16 to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroI32
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI32>>::Error>
pub fn try_from(
value: NonZeroI32
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI32>>::Error>
Attempts to convert NonZeroI32 to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroI64
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI64>>::Error>
pub fn try_from(
value: NonZeroI64
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI64>>::Error>
Attempts to convert NonZeroI64 to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroI8
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI8>>::Error>
pub fn try_from(
value: NonZeroI8
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI8>>::Error>
Attempts to convert NonZeroI8 to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroIsize
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroIsize>>::Error>
pub fn try_from(
value: NonZeroIsize
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroIsize>>::Error>
Attempts to convert NonZeroIsize to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroU128
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU128>>::Error>
pub fn try_from(
value: NonZeroU128
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU128>>::Error>
Attempts to convert NonZeroU128 to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroU32
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU32>>::Error>
pub fn try_from(
value: NonZeroU32
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU32>>::Error>
Attempts to convert NonZeroU32 to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroU64
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU64>>::Error>
pub fn try_from(
value: NonZeroU64
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64 to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU128, <NonZeroU128 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU128, <NonZeroU128 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroU128.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU16, <NonZeroU16 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU16, <NonZeroU16 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroU16.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI128, <NonZeroI128 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI128, <NonZeroI128 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroI128.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI8, <NonZeroI8 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI8, <NonZeroI8 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroIsize, <NonZeroIsize as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroIsize, <NonZeroIsize as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroU32.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI64, <NonZeroI64 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI64, <NonZeroI64 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroI64.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI16, <NonZeroI16 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI16, <NonZeroI16 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroI16.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroU64.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI32, <NonZeroI32 as TryFrom<NonZeroUsize>>::Error>
pub fn try_from(
value: NonZeroUsize
) -> Result<NonZeroI32, <NonZeroI32 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroI32.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
pub fn try_from(
value: usize
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<usize>>::Error>
pub fn try_from(
value: usize
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<usize>>::Error>
Attempts to convert usize to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Auto Trait Implementations
impl RefUnwindSafe for NonZeroUsize
impl Send for NonZeroUsize
impl Sync for NonZeroUsize
impl Unpin for NonZeroUsize
impl UnwindSafe for NonZeroUsize
Blanket Implementations
Mutably borrows from an owned value. Read more
Causes self to use its Binary implementation when Debug-formatted.
Causes self to use its Display implementation when
Debug-formatted. Read more
Causes self to use its LowerExp implementation when
Debug-formatted. Read more
Causes self to use its LowerHex implementation when
Debug-formatted. Read more
Causes self to use its Octal implementation when Debug-formatted.
Causes self to use its Pointer implementation when
Debug-formatted. Read more
Causes self to use its UpperExp implementation when
Debug-formatted. Read more
Causes self to use its UpperHex implementation when
Debug-formatted. Read more
Pipes by value. This is generally the method you want to use. Read more
Borrows self and passes that borrow into the pipe function. Read more
Mutably borrows self and passes that borrow into the pipe function. Read more
Borrows self, then passes self.borrow() into the pipe function. Read more
Mutably borrows self, then passes self.borrow_mut() into the pipe
function. Read more
Borrows self, then passes self.as_ref() into the pipe function.
Mutably borrows self, then passes self.as_mut() into the pipe
function. Read more
Borrows self, then passes self.deref() into the pipe function.
fn pipe_as_ref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: AsRef<T>,
T: 'a,
R: 'a,
fn pipe_as_ref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: AsRef<T>,
T: 'a,
R: 'a,
Pipes a trait borrow into a function that cannot normally be called in suffix position. Read more
fn pipe_borrow<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: Borrow<T>,
T: 'a,
R: 'a,
fn pipe_borrow<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: Borrow<T>,
T: 'a,
R: 'a,
Pipes a trait borrow into a function that cannot normally be called in suffix position. Read more
fn pipe_deref<'a, R>(&'a self, func: impl FnOnce(&'a Self::Target) -> R) -> R where
Self: Deref,
R: 'a,
fn pipe_deref<'a, R>(&'a self, func: impl FnOnce(&'a Self::Target) -> R) -> R where
Self: Deref,
R: 'a,
Pipes a dereference into a function that cannot normally be called in suffix position. Read more
Pipes a reference into a function that cannot ordinarily be called in suffix position. Read more
Immutable access to the Borrow<B> of a value. Read more
Mutable access to the BorrowMut<B> of a value. Read more
Immutable access to the AsRef<R> view of a value. Read more
Mutable access to the AsMut<R> view of a value. Read more
Immutable access to the Deref::Target of a value. Read more
Mutable access to the Deref::Target of a value. Read more
Calls .tap() only in debug builds, and is erased in release builds.
Calls .tap_mut() only in debug builds, and is erased in release
builds. Read more
Calls .tap_borrow() only in debug builds, and is erased in release
builds. Read more
Calls .tap_borrow_mut() only in debug builds, and is erased in release
builds. Read more
Calls .tap_ref() only in debug builds, and is erased in release
builds. Read more
Calls .tap_ref_mut() only in debug builds, and is erased in release
builds. Read more
Calls .tap_deref() only in debug builds, and is erased in release
builds. Read more
Provides immutable access to the reference for inspection.
Calls tap_ref in debug builds, and does nothing in release builds.
Provides mutable access to the reference for modification.
Calls tap_ref_mut in debug builds, and does nothing in release builds.
Provides immutable access to the borrow for inspection. Read more
Calls tap_borrow in debug builds, and does nothing in release builds.
fn tap_borrow_mut<F, R>(self, func: F) -> Self where
Self: BorrowMut<T>,
F: FnOnce(&mut T) -> R,
fn tap_borrow_mut<F, R>(self, func: F) -> Self where
Self: BorrowMut<T>,
F: FnOnce(&mut T) -> R,
Provides mutable access to the borrow for modification.
Immutably dereferences self for inspection.
fn tap_deref_dbg<F, R>(self, func: F) -> Self where
Self: Deref,
F: FnOnce(&Self::Target) -> R,
fn tap_deref_dbg<F, R>(self, func: F) -> Self where
Self: Deref,
F: FnOnce(&Self::Target) -> R,
Calls tap_deref in debug builds, and does nothing in release builds.
fn tap_deref_mut<F, R>(self, func: F) -> Self where
Self: DerefMut,
F: FnOnce(&mut Self::Target) -> R,
fn tap_deref_mut<F, R>(self, func: F) -> Self where
Self: DerefMut,
F: FnOnce(&mut Self::Target) -> R,
Mutably dereferences self for modification.