bjoernager/rust
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Use iter::zip in compiler/

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This commit is contained in:
Josh Stone 2021-03-08 15:32:41 -08:00
parent 3b1f5e3462
commit 72ebebe474
87 changed files with 213 additions and 204 deletions
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33
compiler/rustc_trait_selection/src/traits/coherence.rs
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@ -74,23 +74,22 @@ where
let impl2_ref = tcx.impl_trait_ref(impl2_def_id);
// Check if any of the input types definitely do not unify.
if impl1_ref
.iter()
.flat_map(|tref| tref.substs.types())
.zip(impl2_ref.iter().flat_map(|tref| tref.substs.types()))
.any(|(ty1, ty2)| {
let t1 = fast_reject::simplify_type(tcx, ty1, false);
let t2 = fast_reject::simplify_type(tcx, ty2, false);
if let (Some(t1), Some(t2)) = (t1, t2) {
// Simplified successfully
// Types cannot unify if they differ in their reference mutability or simplify to different types
t1 != t2 || ty1.ref_mutability() != ty2.ref_mutability()
} else {
// Types might unify
false
}
})
{
if iter::zip(
impl1_ref.iter().flat_map(|tref| tref.substs.types()),
impl2_ref.iter().flat_map(|tref| tref.substs.types()),
)
.any(|(ty1, ty2)| {
let t1 = fast_reject::simplify_type(tcx, ty1, false);
let t2 = fast_reject::simplify_type(tcx, ty2, false);
if let (Some(t1), Some(t2)) = (t1, t2) {
// Simplified successfully
// Types cannot unify if they differ in their reference mutability or simplify to different types
t1 != t2 || ty1.ref_mutability() != ty2.ref_mutability()
} else {
// Types might unify
false
}
}) {
// Some types involved are definitely different, so the impls couldn't possibly overlap.
debug!("overlapping_impls: fast_reject early-exit");
return no_overlap();