Struct rfw_utils::BitRef [−][src]
#[repr(C, align(8))]pub struct BitRef<'a, M, O = Lsb0, T = usize> where
T: BitStore,
O: BitOrder,
M: Mutability, { /* fields omitted */ }
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 theBitRef
.
Type Parameters
M
: The write permission of the reference. When this isConst
, theDerefMut
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.
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.
Methods from Deref<Target = bool>
Trait Implementations
DO NOT use this. You clearly have a BitSlice
. Use
BitVec::extend_from_bitslice
.
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
DO NOT use this. You clearly have a BitSlice
. Use
BitVec::from_bitslice
instead.
Implement ordering by comparing the proxied bool
values.
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 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
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 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
Implement equality by comparing the proxied bool
values.
Auto Trait Implementations
impl<'a, M, O = Lsb0, T = usize> !RefUnwindSafe for BitRef<'a, M, O, T>
impl<'a, M, O = Lsb0, T = usize> !UnwindSafe for BitRef<'a, M, O, T>
Blanket Implementations
Mutably borrows from an owned value. Read more
fn fmt_binary(self) -> FmtBinary<Self> where
Self: Binary,
fn fmt_binary(self) -> FmtBinary<Self> where
Self: Binary,
Causes self
to use its Binary
implementation when Debug
-formatted.
fn fmt_display(self) -> FmtDisplay<Self> where
Self: Display,
fn fmt_display(self) -> FmtDisplay<Self> where
Self: Display,
Causes self
to use its Display
implementation when
Debug
-formatted. Read more
fn fmt_lower_exp(self) -> FmtLowerExp<Self> where
Self: LowerExp,
fn fmt_lower_exp(self) -> FmtLowerExp<Self> where
Self: LowerExp,
Causes self
to use its LowerExp
implementation when
Debug
-formatted. Read more
fn fmt_lower_hex(self) -> FmtLowerHex<Self> where
Self: LowerHex,
fn fmt_lower_hex(self) -> FmtLowerHex<Self> where
Self: LowerHex,
Causes self
to use its LowerHex
implementation when
Debug
-formatted. Read more
Causes self
to use its Octal
implementation when Debug
-formatted.
fn fmt_pointer(self) -> FmtPointer<Self> where
Self: Pointer,
fn fmt_pointer(self) -> FmtPointer<Self> where
Self: Pointer,
Causes self
to use its Pointer
implementation when
Debug
-formatted. Read more
fn fmt_upper_exp(self) -> FmtUpperExp<Self> where
Self: UpperExp,
fn fmt_upper_exp(self) -> FmtUpperExp<Self> where
Self: UpperExp,
Causes self
to use its UpperExp
implementation when
Debug
-formatted. Read more
fn fmt_upper_hex(self) -> FmtUpperHex<Self> where
Self: UpperHex,
fn fmt_upper_hex(self) -> FmtUpperHex<Self> where
Self: UpperHex,
Causes self
to use its UpperHex
implementation when
Debug
-formatted. Read more
impl<T> Pipe for T where
T: ?Sized,
impl<T> Pipe for T where
T: ?Sized,
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
fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R where
R: 'a,
fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R where
R: 'a,
Mutably borrows self
and passes that borrow into the pipe function. Read more
fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R where
Self: Borrow<B>,
R: 'a,
B: 'a + ?Sized,
fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R where
Self: Borrow<B>,
R: 'a,
B: 'a + ?Sized,
Borrows self
, then passes self.borrow()
into the pipe function. Read more
fn pipe_borrow_mut<'a, B, R>(
&'a mut self,
func: impl FnOnce(&'a mut B) -> R
) -> R where
Self: BorrowMut<B>,
R: 'a,
B: 'a + ?Sized,
fn pipe_borrow_mut<'a, B, R>(
&'a mut self,
func: impl FnOnce(&'a mut B) -> R
) -> R where
Self: BorrowMut<B>,
R: 'a,
B: 'a + ?Sized,
Mutably borrows self
, then passes self.borrow_mut()
into the pipe
function. Read more
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R where
Self: AsRef<U>,
R: 'a,
U: 'a + ?Sized,
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R where
Self: AsRef<U>,
R: 'a,
U: 'a + ?Sized,
Borrows self
, then passes self.as_ref()
into the pipe function.
fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R where
Self: AsMut<U>,
R: 'a,
U: 'a + ?Sized,
fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R where
Self: AsMut<U>,
R: 'a,
U: 'a + ?Sized,
Mutably borrows self
, then passes self.as_mut()
into the pipe
function. Read more
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: Deref<Target = T>,
T: 'a + ?Sized,
R: 'a,
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: Deref<Target = T>,
T: 'a + ?Sized,
R: 'a,
Borrows self
, then passes self.deref()
into the pipe function.
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
Immutable access to the Borrow<B>
of a value. Read more
fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
Mutable access to the BorrowMut<B>
of a value. Read more
Immutable access to the AsRef<R>
view of a value. Read more
fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
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.
fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self
fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self
Calls .tap_mut()
only in debug builds, and is erased in release
builds. Read more
fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
Calls .tap_borrow()
only in debug builds, and is erased in release
builds. Read more
fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
Calls .tap_borrow_mut()
only in debug builds, and is erased in release
builds. Read more
fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self where
Self: AsRef<R>,
R: ?Sized,
fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self where
Self: AsRef<R>,
R: ?Sized,
Calls .tap_ref()
only in debug builds, and is erased in release
builds. Read more
fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
Calls .tap_ref_mut()
only in debug builds, and is erased in release
builds. Read more