| //@ build-pass |
| #![crate_type = "lib"] |
| #![allow(arithmetic_overflow)] |
| |
| pub trait BitSplit { |
| type Half; |
| fn merge(halves: [Self::Half; 2]) -> Self; |
| } |
| |
| macro_rules! impl_ints { |
| ($int:ty => $half:ty; $mask:expr) => { |
| impl BitSplit for $int { |
| type Half = $half; |
| #[inline] |
| fn merge(halves: [Self::Half; 2]) -> Self { |
| const HALF_SIZE: usize = std::mem::size_of::<$half>() * 8; |
| (halves[0] << HALF_SIZE) as $int | halves[1] as $int |
| } |
| } |
| }; |
| } |
| |
| impl_ints!(u128 => u64; 0x0000_0000_0000_0000_FFFF_FFFF_FFFF_FFFF); |
| impl_ints!( u64 => u32; 0x0000_0000_FFFF_FFFF); |
| impl_ints!( u32 => u16; 0x0000_FFFF); |
| impl_ints!( u16 => u8; 0x00FF); |