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