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The lifetime annotations on BitSliceMut::from_slice can lead to undefined behavior. The following example fails Miri.

extern crate bv;

use bv::{BitVec, BlockType, BitSliceMut, Bits, BitSlice};

fn main() {
    let mut myvec: Vec<usize> = Vec::from([0, 1, 0, 1, 1, 0, 0, 1]);

    let mut slice = &mut myvec[..];
    let mut bitslice = BitSliceMut::from_slice(slice);

    drop(slice); // This shouldn't be allowed
    let bit = bitslice.get_bit(2);
    println!("Bit at position 2: {}", bit);
}

The current signature of this function is

impl<'a, Block: BlockType> BitSliceMut<'a, Block> {
    /// Creates a `BitSliceMut` from a mutable array slice of blocks.
    ///
    /// The size is always a multiple of `Block::nbits()`. If you want a different size,
    /// slice.
    pub fn from_slice(blocks: &mut [Block]) -> Self {

This allows Self to outlive the slice. If this were modified as:

impl<'a, Block: BlockType> BitSliceMut<'a, Block> {
    /// Creates a `BitSliceMut` from a mutable array slice of blocks.
    ///
    /// The size is always a multiple of `Block::nbits()`. If you want a different size,
    /// slice.
    pub fn from_slice(blocks: &'a mut [Block]) -> Self {

This would prevent the earlier example from compiling and ensure safety.

Hi, your library looks like it's largely suiting my needs to modify generic bitsets of arbitrary length, but I was just wondering if there was a way to set the first N bits of a BitsT : BitsMut object. I could go with Default::default() and set the first N bits in a loop but this approach seemed slow, especially in the case BitT was a multiword bitset. set_bits() seemed to be what I was looking by it's name but the value argument was Block, not bool so this confused me as to it's usage. Any help appreciated.

i wanted to iterate over every value in the bitvec to append it to another bitvec (I have a HashMap of Value,BitVec)
but there is no way to iterate over each individual bit