solang_parser/helpers/
ord.rs

1// SPDX-License-Identifier: Apache-2.0
2
3//! Implements `PartialOrd` and `Ord` for some parse tree data types, following the
4//! [Solidity style guide][ref].
5//!
6//! [ref]: https://docs.soliditylang.org/en/latest/style-guide.html
7
8use crate::pt;
9use std::cmp::Ordering;
10
11macro_rules! impl_with_cast {
12    ($($t:ty),+) => {
13        $(
14            impl $t {
15                #[inline]
16                const fn as_discriminant(&self) -> &u8 {
17                    // SAFETY: See <https://doc.rust-lang.org/stable/std/mem/fn.discriminant.html#accessing-the-numeric-value-of-the-discriminant>
18                    // and <https://doc.rust-lang.org/reference/items/enumerations.html#pointer-casting>
19                    //
20                    // `$t` must be `repr(u8)` for this to be safe.
21                    unsafe { &*(self as *const Self as *const u8) }
22                }
23            }
24
25            impl PartialOrd for $t {
26                #[inline]
27                fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
28                    Some(self.cmp(other))
29                }
30            }
31
32            impl Ord for $t {
33                #[inline]
34                fn cmp(&self, other: &Self) -> Ordering {
35                    Ord::cmp(self.as_discriminant(), other.as_discriminant())
36                }
37            }
38        )+
39    };
40}
41
42// SAFETY: every type must be `repr(u8)` for this to be safe, see comments in macro implementation.
43impl_with_cast!(pt::Visibility, pt::VariableAttribute, pt::FunctionAttribute);
solang_parser/helpers/ord.rs

solang_parser/helpers/
ord.rs
