#[repr(C, align(8))]
pub struct BitRef<'a, M, O = Lsb0, T = usize> where
    M: Mutability,
    O: BitOrder,
    T: BitStore
{ /* private fields */ }
Expand description

A proxy reference, equivalent to C++ std::bitset<N>::reference.

This type wraps a BitPtr and caches a bool in a padding byte. It is then able to freely produce references to the cached bool, and commits the cache back to the referent bit location on drop.

Lifetimes

  • 'a: The lifetime of the source &'a mut BitSlice that created the BitRef.

Type Parameters

  • M: The write permission of the reference. When this is Const, the DerefMut implementation is removed, forbidding the proxy from writing back to memory.
  • O: The ordering used to address a bit in memory.
  • T: The storage type containing the referent bit.

Quirks

Because this type has both a lifetime and a destructor, it can introduce an uncommon error condition in Rust. When an expression that produces this type is in the final expression of a block, including if that expression is used as a condition in a match, if let, or if, then the compiler will attempt to extend the drop scope of this type to the outside of the block. This causes a lifetime mismatch error if the source region from which this proxy is produced goes out of scope at the end of the block.

If you get a compiler error that this type causes something to be dropped while borrowed, you can end the borrow by putting any expression-ending syntax element after the offending expression that produces this type, including a semicolon or an item definition.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 2];

let (left, right) = bits.split_at_mut(1);
let mut first = left.get_mut(0).unwrap();
let second = right.get_mut(0).unwrap();

// Referential behavior
*first = true;
// Direct write
second.set(true);

drop(first); // it’s not a reference!
assert_eq!(bits, bits![1; 2]);

Implementations

Converts a bit-pointer into a proxy bit-reference.

The conversion reads from the pointer, then stores the bool in a padding byte.

Parameters
  • bitptr: A bit-pointer to turn into a bit-reference.
Returns

A bit-reference pointing at bitptr.

Safety

The bitptr must address a location that is valid for reads and, if M is Mut, writes.

Decays the bit-reference to an ordinary bit-pointer.

Parameters
  • self
Returns

The interior bit-pointer, without the associated cache. If this was a write-capable pointer, then the cached bit is committed to memory before this method returns.

Moves src into the referenced bit, returning the previous value.

Original

mem::replace

Swaps the values at two mutable locations, without deïnitializing either one.

Original

mem::swap

Writes a bit into the proxied location without an intermediate copy.

This function writes value directly into the proxied location, and does not store value in the proxy’s internal cache. This should be equivalent to the behavior seen when using ordinary DerefMut proxying, but the latter depends on compiler optimization.

Parameters
  • self: This destroys the proxy, as it becomes invalid when writing directly to the location without updating the cache.
  • value: The new bit to write into the proxied slot.

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

The resulting type after dereferencing.

Dereferences the value.

Mutably dereferences the value.

Formats the value using the given formatter. Read more

Executes the destructor for this type. Read more

Extends a collection with the contents of an iterator. Read more

🔬 This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

🔬 This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements. Read more

Creates a value from an iterator. Read more

Feeds this value into the given Hasher. Read more

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

The resulting type after applying the ! operator.

Performs the unary ! operation. Read more

Implement ordering by comparing the proxied bool values.

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 !=.

Test equality of proxy references by the value of their proxied bit.

To test equality by address, decay to a BitPtr with into_bitptr.

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

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

Order proxy references by the value of their proxied bit.

To order by address, decay to a BitPtr with into_bitptr.

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

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

Formats the value using the given formatter.

Implement equality by comparing the proxied bool values.

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

Converts self into T using Into<T>. Read more

Converts self into a target type. 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

Performs the conversion.

Performs the conversion.

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.

Mutably borrows self, then passes self.deref_mut() into the pipe function. Read more

Pipes a value into a function that cannot ordinarily be called in suffix position. Read more

Pipes a trait borrow into a function that cannot normally be called in suffix position. Read more

Pipes a trait mutable borrow into a function that cannot normally be called in suffix position. Read more

Pipes a trait borrow into a function that cannot normally be called in suffix position. Read more

Pipes a trait mutable borrow into a function that cannot normally be called in suffix position. Read more

Pipes a dereference into a function that cannot normally be called in suffix position. Read more

Pipes a mutable 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

Pipes a mutable reference into a function that cannot ordinarily be called in suffix position. Read more

Immutable access to a value. Read more

Mutable access to a value. 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

Calls .tap_deref_mut() only in debug builds, and is erased in release builds. Read more

Provides immutable access for inspection. Read more

Calls tap in debug builds, and does nothing in release builds.

Provides mutable access for modification. Read more

Calls tap_mut in debug builds, and does nothing in release builds.

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.

Provides mutable access to the borrow for modification.

Calls tap_borrow_mut in debug builds, and does nothing in release builds. Read more

Immutably dereferences self for inspection.

Calls tap_deref in debug builds, and does nothing in release builds.

Mutably dereferences self for modification.

Calls tap_deref_mut in debug builds, and does nothing in release builds. Read more

The resulting type after obtaining ownership.

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

🔬 This is a nightly-only experimental API. (toowned_clone_into)

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

Converts the given value to a String. Read more

Attempts to convert self into T using TryInto<T>. Read more

Attempts to convert self into a target type. 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.