From a82bae2172499864c12a1d0b412931ad884911f7 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Wed, 24 Jan 2024 22:27:25 +0000
Subject: Teach typeck/borrowck/solvers how to deal with async closures

---
 compiler/rustc_ast_lowering/src/expr.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'compiler/rustc_ast_lowering/src/expr.rs')

diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 2241b4cd8e5..9990d526bf7 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -1,3 +1,5 @@
+use std::assert_matches::assert_matches;
+
 use super::errors::{
     AsyncCoroutinesNotSupported, AwaitOnlyInAsyncFnAndBlocks, BaseExpressionDoubleDot,
     ClosureCannotBeStatic, CoroutineTooManyParameters,
@@ -1027,6 +1029,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
     ) -> hir::ExprKind<'hir> {
         let (binder_clause, generic_params) = self.lower_closure_binder(binder);
 
+        assert_matches!(
+            coroutine_kind,
+            CoroutineKind::Async { .. },
+            "only async closures are supported currently"
+        );
+
         let body = self.with_new_scopes(fn_decl_span, |this| {
             let inner_decl =
                 FnDecl { inputs: decl.inputs.clone(), output: FnRetTy::Default(fn_decl_span) };
-- 
cgit 1.4.1-3-g733a5