Struct rocket_governor::NonZeroU32

1.28.0 · source · []
#[repr(transparent)]
pub struct NonZeroU32(_);
Expand description

An integer that is known not to equal zero.

This enables some memory layout optimization. For example, Option<NonZeroU32> is the same size as u32:

use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroU32>>(), size_of::<u32>());

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 value as a primitive type.

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::NonZeroU32::new(u32::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::NonZeroU32::new(0b0101000).unwrap();

assert_eq!(n.trailing_zeros(), 3);
🔬 This is a nightly-only experimental API. (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 = NonZeroU32::new(1)?;
let two = NonZeroU32::new(2)?;
let max = NonZeroU32::new(u32::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)

Add an unsigned integer to a non-zero value. Return u32::MAX on overflow.

Examples
#![feature(nonzero_ops)]

let one = NonZeroU32::new(1)?;
let two = NonZeroU32::new(2)?;
let max = NonZeroU32::new(u32::MAX)?;

assert_eq!(two, one.saturating_add(1));
assert_eq!(max, max.saturating_add(1));
🔬 This is a nightly-only experimental API. (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 > u32::MAX.

Examples
#![feature(nonzero_ops)]

let one = NonZeroU32::new(1)?;
let two = NonZeroU32::new(2)?;

assert_eq!(two, unsafe { one.unchecked_add(1) });
🔬 This is a nightly-only experimental API. (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 = NonZeroU32::new(2)?;
let three = NonZeroU32::new(3)?;
let four = NonZeroU32::new(4)?;
let max = NonZeroU32::new(u32::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)

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

This is the same operation as u32::log2, except that it has no failure cases to worry about since this value can never be zero.

Examples
#![feature(int_log)]

assert_eq!(NonZeroU32::new(7).unwrap().log2(), 2);
assert_eq!(NonZeroU32::new(8).unwrap().log2(), 3);
assert_eq!(NonZeroU32::new(9).unwrap().log2(), 3);
🔬 This is a nightly-only experimental API. (int_log)

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

This is the same operation as u32::log10, except that it has no failure cases to worry about since this value can never be zero.

Examples
#![feature(int_log)]

assert_eq!(NonZeroU32::new(99).unwrap().log10(), 1);
assert_eq!(NonZeroU32::new(100).unwrap().log10(), 2);
assert_eq!(NonZeroU32::new(101).unwrap().log10(), 2);
🔬 This is a nightly-only experimental API. (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 = NonZeroU32::new(2)?;
let four = NonZeroU32::new(4)?;
let max = NonZeroU32::new(u32::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)

Multiply two non-zero integers together. Return u32::MAX on overflow.

Examples
#![feature(nonzero_ops)]

let two = NonZeroU32::new(2)?;
let four = NonZeroU32::new(4)?;
let max = NonZeroU32::new(u32::MAX)?;

assert_eq!(four, two.saturating_mul(two));
assert_eq!(max, four.saturating_mul(max));
🔬 This is a nightly-only experimental API. (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 > u32::MAX.

Examples
#![feature(nonzero_ops)]

let two = NonZeroU32::new(2)?;
let four = NonZeroU32::new(4)?;

assert_eq!(four, unsafe { two.unchecked_mul(two) });
🔬 This is a nightly-only experimental API. (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 = NonZeroU32::new(3)?;
let twenty_seven = NonZeroU32::new(27)?;
let half_max = NonZeroU32::new(u32::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)

Raise non-zero value to an integer power. Return u32::MAX on overflow.

Examples
#![feature(nonzero_ops)]

let three = NonZeroU32::new(3)?;
let twenty_seven = NonZeroU32::new(27)?;
let max = NonZeroU32::new(u32::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::NonZeroU32::new(8).unwrap();
assert!(eight.is_power_of_two());
let ten = std::num::NonZeroU32::new(10).unwrap();
assert!(!ten.is_power_of_two());
🔬 This is a nightly-only experimental API. (nonzero_min_max)

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

Examples
#![feature(nonzero_min_max)]

assert_eq!(NonZeroU32::MIN.get(), 1u32);
🔬 This is a nightly-only experimental API. (nonzero_min_max)

The largest value that can be represented by this non-zero integer type, equal to u32::MAX.

Examples
#![feature(nonzero_min_max)]

assert_eq!(NonZeroU32::MAX.get(), u32::MAX);
🔬 This is a nightly-only experimental API. (nonzero_bits)

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

This value is equal to u32::BITS.

Examples
#![feature(nonzero_bits)]

assert_eq!(NonZeroU32::BITS, u32::BITS);

Trait Implementations

Formats the value using the given formatter.

The resulting type after applying the | operator.

Performs the | operation. Read more

The resulting type after applying the | operator.

Performs the | operation. Read more

Performs the |= operation. Read more

Performs the |= operation. Read more

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Deserialize this value from the given Serde deserializer. Read more

Formats the value using the given formatter. Read more

Converts NonZeroU16 to NonZeroU32 losslessly.

Converts NonZeroU8 to NonZeroU32 losslessly.

Parse a value of T from a form value field. Read more

Parse a value of T from a form data field. Read more

Returns a default value, if any exists, to be used during lenient parsing when the form field is missing. Read more

The associated error to be returned if parsing/validation fails.

Parses and validates an instance of Self from a path parameter string or returns an Error if parsing or validation fails. Read more

The associated error which can be returned from parsing.

Parses a string s to return a value of this type. Read more

The resulting type of this conversion.

Converts a value of type T into a value of type Self::Target. The resulting value of type Self::Target will be rendered into a URI using its [UriDisplay] implementation. Read more

The resulting type of this conversion.

Converts a value of type T into a value of type Self::Target. The resulting value of type Self::Target will be rendered into a URI using its [UriDisplay] implementation. Read more

The resulting type of this conversion.

Converts a value of type T into a value of type Self::Target. The resulting value of type Self::Target will be rendered into a URI using its [UriDisplay] implementation. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

Formats the value using the given formatter.

The primitive type (e.g. u8) underlying this integral type.

Creates a new non-zero object from an integer that might be zero. Read more

Returns the value as a primitive type.

Formats the value using the given formatter.

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Restrict a value to a certain interval. 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

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Serialize this value into the given Serde serializer. Read more

Attempts to convert NonZeroI128 to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert NonZeroI16 to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert NonZeroI32 to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert NonZeroI64 to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert NonZeroI8 to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert NonZeroIsize to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert NonZeroU128 to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert NonZeroU64 to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert NonZeroUsize to NonZeroU32.

The type returned in the event of a conversion error.

Attempts to convert u32 to NonZeroU32.

The type returned in the event of a conversion error.

Formats the value using the given formatter.

This implementation is identical to the Display implementation.

Formats self in a URI-safe manner using the given formatter.

Visits this value with the given Visitor.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Compare self to key and return true if they are equal.

Returns the argument unchanged.

The form guard’s parsing context.

Initializes and returns the parsing context for Self.

Processes the value field field.

Processes the data field field.

Finalizes parsing. Returns the parsed value when successful or collection of Errors otherwise. Read more

Processes the external form or field error _error. Read more

Returns a default value, if any, to use when a value is desired and parsing fails. Read more

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Converts self into a collection.

Should always be Self

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

Converts the given value to a String. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more