Trait bitmap32::BitBlock

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pub unsafe trait BitBlock: Copy + Not<Output = Self> + BitOr<Output = Self> + BitOrAssign + BitAndAssign + BitAnd<Output = Self> + Ord {
    const BITS: usize;
    const ZERO: Self;
    const UPSTREAM_ONE: Self;

    // Required methods
    fn wrapping_shift_downstream(self, n: usize) -> Self;
    fn wrapping_shift_upstream(self, n: usize) -> Self;
    fn leading_zeros(self) -> usize;
    fn leading_ones(self) -> usize;

    // Provided methods
    fn get_block_index(idx: usize) -> usize { ... }
    fn bit_index_from_block_index(idx: usize) -> usize { ... }
    fn wrapping_test_bit(self, idx: usize) -> bool { ... }
    fn wrapping_with_bit(self, idx: usize) -> Self { ... }
    fn wrapping_without_bit(self, idx: usize) -> Self { ... }
    fn ones_mask(position: usize, length: NonZeroUsize) -> Self { ... }
}

Expand description

Represents a copyable container of bits (usually an unsigned integer).

Safety

Self::ZERO must be core::mem::zeroed().
2^BITS_LOG2 must be equal to BITS.
The provided methods can only be overridden with equivalent methods.

Required Associated Constants§

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const BITS: usize

Represents the number of bits in a block. It is generally a good idea for this number to be a power of two.

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const ZERO: Self

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const UPSTREAM_ONE: Self

As of now, this value is not 1 for unsigned integers UPSTREAM_ONE.wrapping_shift_upstream(1) should be 0. For example, for u8, this value is 0x80 (0b10000000).

Required Methods§

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fn wrapping_shift_downstream(self, n: usize) -> Self

Shifts self n bits in the indexing direction.

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fn wrapping_shift_upstream(self, n: usize) -> Self

Shifts self n bits against the indexing direction.

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fn leading_zeros(self) -> usize

Gets the leading zeros in the indexing direction.

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fn leading_ones(self) -> usize

Gets the leading ones in the indexing direction.

Provided Methods§

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fn get_block_index(idx: usize) -> usize

Returns the index of the block holding the bit at the specified location in a collection (eg. for a u8, get_block_index(9) == 2).

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fn bit_index_from_block_index(idx: usize) -> usize

Returns the index of the first bit in the block at idx..

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fn wrapping_test_bit(self, idx: usize) -> bool

Returns true if the bit at idx is 1.

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fn wrapping_with_bit(self, idx: usize) -> Self

Returns self with the bit at idx set to 1.

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fn wrapping_without_bit(self, idx: usize) -> Self

Returns self with the bit at idx set to 0.

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fn ones_mask(position: usize, length: NonZeroUsize) -> Self

Returns a bit mask of ones at position (wrapped) with a length of length (saturated).

Example

assert_eq!(u8::ones_mask(2, NonZeroUsize::new(3).unwrap()), 0b00111000);
assert_eq!(u8::ones_mask(6, NonZeroUsize::new(10).unwrap()), 0b00000011);
assert_eq!(u8::ones_mask(12, NonZeroUsize::new(2).unwrap()), 0b00001100);