fn swap_a(cpu: &mut Cpu) {
        let a = cpu.a();

        let r = swap(cpu, a);

        cpu.set_a(r);
    }
/// Swap low and high nibbles of `A`
Swap low and high nibbles of `A`
Swap low and high nibbles of ` A `
fn swap_a(cpu: &mut Cpu) {
        let a = cpu.a();
        let r = swap(cpu, a);
        cpu.set_a(r);
    }
fn swap_a ( cpu : & mut Cpu ) { let a = cpu . a ( ) ; let r = swap ( cpu , a ) ; cpu . set_a ( r ) ; }
Swap low and high nibbles of `A`
Swap low and high nibbles of ` A `
cpu
&mut Cpu
cpu
&mut Cpu