Rollup merge of #102786 - compiler-errors:no-tuple-candidate, r=lcnr

Remove tuple candidate, nothing special about it

r? `@lcnr` you mentioned this during the talk you gave i think

3 files changed, 2 insertions, 14 deletions

diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 68a7af0b8c8..a635e0463e5 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -664,10 +664,6 @@ pub enum ImplSource<'tcx, N> {
 
     /// ImplSource for a `const Drop` implementation.
     ConstDestruct(ImplSourceConstDestructData<N>),
-
-    /// ImplSource for a `std::marker::Tuple` implementation.
-    /// This has no nested predicates ever, so no data.
-    Tuple,
 }
 
 impl<'tcx, N> ImplSource<'tcx, N> {
@@ -682,8 +678,7 @@ impl<'tcx, N> ImplSource<'tcx, N> {
             ImplSource::Object(d) => d.nested,
             ImplSource::FnPointer(d) => d.nested,
             ImplSource::DiscriminantKind(ImplSourceDiscriminantKindData)
-            | ImplSource::Pointee(ImplSourcePointeeData)
-            | ImplSource::Tuple => Vec::new(),
+            | ImplSource::Pointee(ImplSourcePointeeData) => vec![],
             ImplSource::TraitAlias(d) => d.nested,
             ImplSource::TraitUpcasting(d) => d.nested,
             ImplSource::ConstDestruct(i) => i.nested,
@@ -701,8 +696,7 @@ impl<'tcx, N> ImplSource<'tcx, N> {
             ImplSource::Object(d) => &d.nested,
             ImplSource::FnPointer(d) => &d.nested,
             ImplSource::DiscriminantKind(ImplSourceDiscriminantKindData)
-            | ImplSource::Pointee(ImplSourcePointeeData)
-            | ImplSource::Tuple => &[],
+            | ImplSource::Pointee(ImplSourcePointeeData) => &[],
             ImplSource::TraitAlias(d) => &d.nested,
             ImplSource::TraitUpcasting(d) => &d.nested,
             ImplSource::ConstDestruct(i) => &i.nested,
@@ -769,7 +763,6 @@ impl<'tcx, N> ImplSource<'tcx, N> {
                     nested: i.nested.into_iter().map(f).collect(),
                 })
             }
-            ImplSource::Tuple => ImplSource::Tuple,
         }
     }
 }
diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs
index 11758599cff..85ead3171e7 100644
--- a/compiler/rustc_middle/src/traits/select.rs
+++ b/compiler/rustc_middle/src/traits/select.rs
@@ -161,9 +161,6 @@ pub enum SelectionCandidate<'tcx> {
 
     /// Implementation of `const Destruct`, optionally from a custom `impl const Drop`.
     ConstDestructCandidate(Option<DefId>),
-
-    /// Witnesses the fact that a type is a tuple.
-    TupleCandidate,
 }
 
 /// The result of trait evaluation. The order is important
diff --git a/compiler/rustc_middle/src/traits/structural_impls.rs b/compiler/rustc_middle/src/traits/structural_impls.rs
index c526344e1f2..7fbd57ac735 100644
--- a/compiler/rustc_middle/src/traits/structural_impls.rs
+++ b/compiler/rustc_middle/src/traits/structural_impls.rs
@@ -34,8 +34,6 @@ impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSource<'tcx, N> {
             super::ImplSource::TraitUpcasting(ref d) => write!(f, "{:?}", d),
 
             super::ImplSource::ConstDestruct(ref d) => write!(f, "{:?}", d),
-
-            super::ImplSource::Tuple => write!(f, "ImplSource::Tuple"),
         }
     }
 }