fn parse_add_bits(&mut self) -> Option<()> {
        if self.cur >= self.str_bytes.len() {
            return None;
        }
        let c = self.str_bytes[self.cur];
        self.cur += 1;
        let v = if c <= b'9' { c - b'0' } else { 10 + c - b'A' };
        self.data <<= 4;
        self.data |= v as u32;
        self.len += 4;
        Some(())
    }
/// add 4 bits into the buffer
add 4 bits into the buffer
add 4 bits into the buffer
fn parse_add_bits(&mut self) -> Option<()> {
        if self.cur >= self.str_bytes.len() {
            return None;
        }
        let c = self.str_bytes[self.cur];
        self.cur += 1;
        let v = if c <= b'9' { c - b'0' } else { 10 + c - b'A' };
        self.data <<= 4;
        self.data |= v as u32;
        self.len += 4;
        Some(())
    }
fn parse_add_bits ( & mut self ) -> Option < ( ) > { if self . cur >= self . str_bytes . len ( ) { return None ; } let c = self . str_bytes [ self . cur ] ; self . cur += 1 ; let v = if c <= b'9' { c - b'0' } else { 10 + c - b'A' } ; self . data <<= 4 ; self . data |= v as u32 ; self . len += 4 ; Some ( ( ) ) }
add 4 bits into the buffer
add 4 bits into the buffer
&mut self