Shifting with bytes bits in Rust

byte_bits.rs

fn main() {
    let data: &mut [u8] = &mut [0, 0, 0, 0]; // your byte slice
    let index: usize = 2; // the position where you want to write the byte
    let byte: u8 = 42; // the byte you want to write; 42 => 
    
    // Write the byte to the specified position in the byte slice
    data[index] = byte;
    
    print_byte(&byte);
    
    // switching first bit to 1
    let new_byte = byte | 1 << 0;
    print_byte(&new_byte);
    
    println!("All bytes: {}", format_bytes(data));
}

// fn bits(byte: &u8) -> [u8;8] {
//     let mut bits = [0_u8;8];
//     for i in 0..8 {
//         let mask = 1 << i;
//         let bit_is_set = (mask & byte) > 0;
//         bits[i] = if bit_is_set {
//             1
//         } else {
//             0
//         };
//     }
//     bits
// }

fn format_to_bits(byte: &u8) -> String {
    let mut bits = [0_u8; 8];
    for i in 0..8 {
        let mask = 1 << i;
        let bit_is_set = (mask & byte) > 0;
        bits[i] = if bit_is_set { 1 } else { 0 };
    }
    bits.iter().map(|b| b.to_string()).collect()
}

fn format_bytes(bytes: &[u8]) -> String {
    bytes.iter().map(|b| format!("{:08b},", b)).collect()
}

fn print_byte(byte: &u8) {
    println!("byte {} in bits {:?}", byte, format_to_bits(byte));
}