// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at:
https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
//! ULE impls for tuples.
//!
//! Rust does not guarantee the layout of tuples, so ZeroVec defines its own tuple ULE types.
//!
//! Impls are defined for tuples of up to 6 elements. For longer tuples, use a custom struct
//! with [`#[make_ule]`](crate::make_ule).
//!
//! # Examples
//!
//! ```
//! use zerovec::ZeroVec;
//!
//! // ZeroVec of tuples!
//! let zerovec: ZeroVec<(u32, char)> = [(1, 'a'), (1234901, '啊'), (100, 'अ')]
//! .iter()
//! .copied()
//! .collect();
//!
//! assert_eq!(zerovec.get(1), Some((1234901, '啊')));
//! ```
use super::*;
use core::fmt;
use core::mem;
macro_rules! tuple_ule {
($name:ident, $len:literal, [ $($t:ident $i:tt),+ ]) => {
#[doc = concat!("ULE type for tuples with ", $len, " elements.")]
#[repr(C, packed)]
#[allow(clippy::exhaustive_structs)] // stable
pub struct $name<$($t),+>($(pub $t),+);
// Safety (based on the safety checklist on the ULE trait):
// 1. TupleULE does not include any uninitialized or padding bytes.
// (achieved by `#[repr(C, packed)]` on a struct containing only ULE fields)
// 2. TupleULE is aligned to 1 byte.
// (achieved by `#[repr(C, packed)]` on a struct containing only ULE fields)
// 3. The impl of validate_byte_slice() returns an error if any byte is not valid.
// 4. The impl of validate_byte_slice() returns an error if there are extra bytes.
// 5. The other ULE methods use the default impl.
// 6. TupleULE byte equality is semantic equality by relying on the ULE equality
// invariant on the subfields
unsafe impl<$($t: ULE),+> ULE for $name<$($t),+> {
fn validate_byte_slice(bytes: &[u8]) -> Result<(), ZeroVecError> {
// expands to: 0size + mem::size_of::<A>() + mem::size_of::<B>();
let ule_bytes = 0usize $(+ mem::size_of::<$t>())+;
if bytes.len() % ule_bytes != 0 {
return Err(ZeroVecError::length::<Self>(bytes.len()));
}
for chunk in bytes.chunks(ule_bytes) {
let mut i = 0;
$(
let j = i;
i += mem::size_of::<$t>();
#[allow(clippy::indexing_slicing)] // length checked
<$t>::validate_byte_slice(&chunk[j..i])?;
)+
}
Ok(())
}
}
impl<$($t: AsULE),+> AsULE for ($($t),+) {
type ULE = $name<$(<$t>::ULE),+>;
#[inline]
fn to_unaligned(self) -> Self::ULE {
$name($(
self.$i.to_unaligned()
),+)
}
#[inline]
fn from_unaligned(unaligned: Self::ULE) -> Self {
($(
<$t>::from_unaligned(unaligned.$i)
),+)
}
}
impl<$($t: fmt::Debug + ULE),+> fmt::Debug for $name<$($t),+> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
($(self.$i),+).fmt(f)
}
}
// We need manual impls since `#[derive()]` is disallowed on packed types
impl<$($t: PartialEq + ULE),+> PartialEq for $name<$($t),+> {
fn eq(&self, other: &Self) -> bool {
($(self.$i),+).eq(&($(other.$i),+))
}
}
impl<$($t: Eq + ULE),+> Eq for $name<$($t),+> {}
impl<$($t: PartialOrd + ULE),+> PartialOrd for $name<$($t),+> {
fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
($(self.$i),+).partial_cmp(&($(other.$i),+))
}
}
impl<$($t: Ord + ULE),+> Ord for $name<$($t),+> {
fn cmp(&self, other: &Self) -> core::cmp::Ordering {
($(self.$i),+).cmp(&($(other.$i),+))
}
}
impl<$($t: ULE),+> Clone for $name<$($t),+> {
fn clone(&self) -> Self {
*self
}
}
impl<$($t: ULE),+> Copy for $name<$($t),+> {}
impl<'a, $($t: Ord + AsULE + 'static),+> crate::map::ZeroMapKV<'a> for ($($t),+) {
type Container = crate::ZeroVec<'a, ($($t),+)>;
type Slice = crate::ZeroSlice<($($t),+)>;
type GetType = $name<$(<$t>::ULE),+>;
type OwnedType = ($($t),+);
}
};
}
tuple_ule!(Tuple2ULE, "2", [ A 0, B 1 ]);
tuple_ule!(Tuple3ULE, "3", [ A 0, B 1, C 2 ]);
tuple_ule!(Tuple4ULE, "4", [ A 0, B 1, C 2, D 3 ]);
tuple_ule!(Tuple5ULE, "5", [ A 0, B 1, C 2, D 3, E 4 ]);
tuple_ule!(Tuple6ULE, "6", [ A 0, B 1, C 2, D 3, E 4, F 5 ]);
#[test]
fn test_pairule_validate() {
use crate::ZeroVec;
let vec: Vec<(u32, char)> = vec![(1, 'a'), (1234901, '啊'), (100, 'अ')];
let zerovec: ZeroVec<(u32, char)> = vec.iter().copied().collect();
let bytes = zerovec.as_bytes();
let zerovec2 = ZeroVec::parse_byte_slice(bytes).unwrap();
assert_eq!(zerovec, zerovec2);
// Test failed validation with a correctly sized but differently constrained tuple
// Note: 1234901 is not a valid char
let zerovec3 = ZeroVec::<(char, u32)>::parse_byte_slice(bytes);
assert!(zerovec3.is_err());
}
#[test]
fn test_tripleule_validate() {
use crate::ZeroVec;
let vec: Vec<(u32, char, i8)> = vec![(1, 'a', -5), (1234901, '啊', 3), (100, 'अ', -127)];
let zerovec: ZeroVec<(u32, char, i8)> = vec.iter().copied().collect();
let bytes = zerovec.as_bytes();
let zerovec2 = ZeroVec::parse_byte_slice(bytes).unwrap();
assert_eq!(zerovec, zerovec2);
// Test failed validation with a correctly sized but differently constrained tuple
// Note: 1234901 is not a valid char
let zerovec3 = ZeroVec::<(char, i8, u32)>::parse_byte_slice(bytes);
assert!(zerovec3.is_err());
}
#[test]
fn test_quadule_validate() {
use crate::ZeroVec;
let vec: Vec<(u32, char, i8, u16)> =
vec![(1, 'a', -5, 3), (1234901, '啊', 3, 11), (100, 'अ', -127, 0)];
let zerovec: ZeroVec<(u32, char, i8, u16)> = vec.iter().copied().collect();
let bytes = zerovec.as_bytes();
let zerovec2 = ZeroVec::parse_byte_slice(bytes).unwrap();
assert_eq!(zerovec, zerovec2);
// Test failed validation with a correctly sized but differently constrained tuple
// Note: 1234901 is not a valid char
let zerovec3 = ZeroVec::<(char, i8, u16, u32)>::parse_byte_slice(bytes);
assert!(zerovec3.is_err());
}
