diff options
Diffstat (limited to 'library/core/src/tuple.rs')
| -rw-r--r-- | library/core/src/tuple.rs | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/library/core/src/tuple.rs b/library/core/src/tuple.rs index 206b5b9e2c2..d754bb90343 100644 --- a/library/core/src/tuple.rs +++ b/library/core/src/tuple.rs @@ -2,6 +2,7 @@ use crate::cmp::Ordering::{self, *}; use crate::marker::{ConstParamTy_, StructuralPartialEq, UnsizedConstParamTy}; +use crate::ops::ControlFlow::{Break, Continue}; // Recursive macro for implementing n-ary tuple functions and operations // @@ -80,19 +81,19 @@ macro_rules! tuple_impls { } #[inline] fn lt(&self, other: &($($T,)+)) -> bool { - lexical_ord!(lt, Less, $( ${ignore($T)} self.${index()}, other.${index()} ),+) + lexical_ord!(lt, __chaining_lt, $( ${ignore($T)} self.${index()}, other.${index()} ),+) } #[inline] fn le(&self, other: &($($T,)+)) -> bool { - lexical_ord!(le, Less, $( ${ignore($T)} self.${index()}, other.${index()} ),+) + lexical_ord!(le, __chaining_le, $( ${ignore($T)} self.${index()}, other.${index()} ),+) } #[inline] fn ge(&self, other: &($($T,)+)) -> bool { - lexical_ord!(ge, Greater, $( ${ignore($T)} self.${index()}, other.${index()} ),+) + lexical_ord!(ge, __chaining_ge, $( ${ignore($T)} self.${index()}, other.${index()} ),+) } #[inline] fn gt(&self, other: &($($T,)+)) -> bool { - lexical_ord!(gt, Greater, $( ${ignore($T)} self.${index()}, other.${index()} ),+) + lexical_ord!(gt, __chaining_gt, $( ${ignore($T)} self.${index()}, other.${index()} ),+) } } } @@ -171,15 +172,16 @@ macro_rules! maybe_tuple_doc { // `(a1, a2, a3) < (b1, b2, b3)` would be `lexical_ord!(lt, opt_is_lt, a1, b1, // a2, b2, a3, b3)` (and similarly for `lexical_cmp`) // -// `$ne_rel` is only used to determine the result after checking that they're -// not equal, so `lt` and `le` can both just use `Less`. +// `$chain_rel` is the chaining method from `PartialOrd` to use for all but the +// final value, to produce better results for simple primitives. macro_rules! lexical_ord { - ($rel: ident, $ne_rel: ident, $a:expr, $b:expr, $($rest_a:expr, $rest_b:expr),+) => {{ - let c = PartialOrd::partial_cmp(&$a, &$b); - if c != Some(Equal) { c == Some($ne_rel) } - else { lexical_ord!($rel, $ne_rel, $($rest_a, $rest_b),+) } + ($rel: ident, $chain_rel: ident, $a:expr, $b:expr, $($rest_a:expr, $rest_b:expr),+) => {{ + match PartialOrd::$chain_rel(&$a, &$b) { + Break(val) => val, + Continue(()) => lexical_ord!($rel, $chain_rel, $($rest_a, $rest_b),+), + } }}; - ($rel: ident, $ne_rel: ident, $a:expr, $b:expr) => { + ($rel: ident, $chain_rel: ident, $a:expr, $b:expr) => { // Use the specific method for the last element PartialOrd::$rel(&$a, &$b) }; |
