fn swap_h(cpu: &mut Cpu) {
        let h = cpu.h();

        let r = swap(cpu, h);

        cpu.set_h(r);
    }
/// Swap low and high nibbles of `H`
Swap low and high nibbles of `H`
Swap low and high nibbles of ` H `
fn swap_h(cpu: &mut Cpu) {
        let h = cpu.h();
        let r = swap(cpu, h);
        cpu.set_h(r);
    }
fn swap_h ( cpu : & mut Cpu ) { let h = cpu . h ( ) ; let r = swap ( cpu , h ) ; cpu . set_h ( r ) ; }
Swap low and high nibbles of `H`
Swap low and high nibbles of ` H `
cpu
&mut Cpu
cpu
&mut Cpu