fn swap_c(cpu: &mut Cpu) {
        let c = cpu.c();

        let r = swap(cpu, c);

        cpu.set_c(r);
    }
/// Swap low and high nibbles of `C`
Swap low and high nibbles of `C`
Swap low and high nibbles of ` C `
fn swap_c(cpu: &mut Cpu) {
        let c = cpu.c();
        let r = swap(cpu, c);
        cpu.set_c(r);
    }
fn swap_c ( cpu : & mut Cpu ) { let c = cpu . c ( ) ; let r = swap ( cpu , c ) ; cpu . set_c ( r ) ; }
Swap low and high nibbles of `C`
Swap low and high nibbles of ` C `
cpu
&mut Cpu
cpu
&mut Cpu