From abe040d876f697ef86b1ad395caf68c03ecbf046 Mon Sep 17 00:00:00 2001
From: kadmin <julianknodt@gmail.com>
Date: Sun, 4 Dec 2022 19:58:03 +0000
Subject: [PATCH] Change commit_if_ok to probe

---
 .../src/traits/const_evaluatable.rs           | 11 ++----
 .../const_kind_expr/wf_obligation.rs          |  3 +-
 .../const_kind_expr/wf_obligation.stderr      | 12 +------
 .../ui/const-generics/issues/issue-105037.rs  | 35 +++++++++++++++++++
 4 files changed, 40 insertions(+), 21 deletions(-)
 create mode 100644 src/test/ui/const-generics/issues/issue-105037.rs

diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
index f8efe9bfa9f..f449d360c16 100644
--- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
+++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
@@ -173,16 +173,11 @@ impl<'a, 'tcx> TypeVisitor<'tcx> for Visitor<'a, 'tcx> {
         type BreakTy = ();
         fn visit_const(&mut self, c: ty::Const<'tcx>) -> ControlFlow<Self::BreakTy> {
             debug!("is_const_evaluatable: candidate={:?}", c);
-            if let Ok(()) = self.infcx.commit_if_ok(|_| {
+            if self.infcx.probe(|_| {
                 let ocx = ObligationCtxt::new_in_snapshot(self.infcx);
-                if let Ok(()) = ocx.eq(&ObligationCause::dummy(), self.param_env, c.ty(), self.ct.ty())
-                    && let Ok(()) = ocx.eq(&ObligationCause::dummy(), self.param_env, c, self.ct)
+                ocx.eq(&ObligationCause::dummy(), self.param_env, c.ty(), self.ct.ty()).is_ok()
+                    && ocx.eq(&ObligationCause::dummy(), self.param_env, c, self.ct).is_ok()
                     && ocx.select_all_or_error().is_empty()
-                {
-                    Ok(())
-                } else {
-                    Err(())
-                }
             }) {
                 ControlFlow::BREAK
             } else if let ty::ConstKind::Expr(e) = c.kind() {
diff --git a/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.rs b/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.rs
index 6093fc70b16..b96e210808b 100644
--- a/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.rs
+++ b/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.rs
@@ -15,8 +15,7 @@ fn ice<const L: usize>()
     [(); (L - 1) + 1 + L]:,
 {
     foo::<_, L>([(); L + 1 + L]);
-    //~^ ERROR: mismatched types
-    //~^^ ERROR: unconstrained generic constant
+    //~^ ERROR: unconstrained generic constant
 }
 
 fn main() {}
diff --git a/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.stderr b/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.stderr
index da5194696e6..09e5e3f862a 100644
--- a/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.stderr
+++ b/src/test/ui/const-generics/generic_const_exprs/const_kind_expr/wf_obligation.stderr
@@ -1,12 +1,3 @@
-error[E0308]: mismatched types
-  --> $DIR/wf_obligation.rs:17:17
-   |
-LL |     foo::<_, L>([(); L + 1 + L]);
-   |                 ^^^^^^^^^^^^^^^ expected `N + 1 + M`, found `L + 1 + L`
-   |
-   = note: expected constant `N + 1 + M`
-              found constant `L + 1 + L`
-
 error: unconstrained generic constant
   --> $DIR/wf_obligation.rs:17:22
    |
@@ -15,6 +6,5 @@ LL |     foo::<_, L>([(); L + 1 + L]);
    |
    = help: try adding a `where` bound using this expression: `where [(); L + 1 + L]:`
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/const-generics/issues/issue-105037.rs b/src/test/ui/const-generics/issues/issue-105037.rs
new file mode 100644
index 00000000000..f7d23949943
--- /dev/null
+++ b/src/test/ui/const-generics/issues/issue-105037.rs
@@ -0,0 +1,35 @@
+// run-pass
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+#![allow(dead_code)]
+
+trait Table<const D: usize>: Sync {
+    const COLUMNS: usize;
+}
+
+struct Table1<const D: usize>;
+impl<const D: usize> Table<D> for Table1<D> {
+    const COLUMNS: usize = 123;
+}
+
+struct Table2<const D: usize>;
+impl<const D: usize> Table<D> for Table2<D> {
+    const COLUMNS: usize = 456;
+}
+
+fn process_table<T: Table<D>, const D: usize>(_table: T)
+where
+    [(); T::COLUMNS]:,
+{
+}
+
+fn process_all_tables<const D: usize>()
+where
+    [(); Table2::<D>::COLUMNS]:,
+    [(); Table1::<D>::COLUMNS]:,
+{
+    process_table(Table1::<D>);
+    process_table(Table2::<D>);
+}
+
+fn main() {}