1 files changed, 88 insertions, 0 deletions
diff --git a/tests/ui/async-await/generics-and-bounds.rs b/tests/ui/async-await/generics-and-bounds.rs
new file mode 100644
index 000000000..963b19b34
--- /dev/null
+++ b/tests/ui/async-await/generics-and-bounds.rs
@@ -0,0 +1,88 @@
+// build-pass (FIXME(62277): could be check-pass?)
+// edition:2018
+// compile-flags: --crate-type lib
+
+use std::future::Future;
+
+pub async fn simple_generic<T>() {}
+
+pub trait Foo {
+    fn foo(&self) {}
+}
+
+struct FooType;
+impl Foo for FooType {}
+
+pub async fn call_generic_bound<F: Foo>(f: F) {
+    f.foo()
+}
+
+pub async fn call_where_clause<F>(f: F)
+where
+    F: Foo,
+{
+    f.foo()
+}
+
+pub async fn call_impl_trait(f: impl Foo) {
+    f.foo()
+}
+
+pub async fn call_with_ref(f: &impl Foo) {
+    f.foo()
+}
+
+pub fn async_fn_with_same_generic_params_unifies() {
+    let mut a = call_generic_bound(FooType);
+    a = call_generic_bound(FooType);
+
+    let mut b = call_where_clause(FooType);
+    b = call_where_clause(FooType);
+
+    let mut c = call_impl_trait(FooType);
+    c = call_impl_trait(FooType);
+
+    let f_one = FooType;
+    let f_two = FooType;
+    let mut d = call_with_ref(&f_one);
+    d = call_with_ref(&f_two);
+}
+
+pub fn simple_generic_block<T>() -> impl Future<Output = ()> {
+    async move {}
+}
+
+pub fn call_generic_bound_block<F: Foo>(f: F) -> impl Future<Output = ()> {
+    async move { f.foo() }
+}
+
+pub fn call_where_clause_block<F>(f: F) -> impl Future<Output = ()>
+where
+    F: Foo,
+{
+    async move { f.foo() }
+}
+
+pub fn call_impl_trait_block(f: impl Foo) -> impl Future<Output = ()> {
+    async move { f.foo() }
+}
+
+pub fn call_with_ref_block<'a>(f: &'a (impl Foo + 'a)) -> impl Future<Output = ()> + 'a {
+    async move { f.foo() }
+}
+
+pub fn async_block_with_same_generic_params_unifies() {
+    let mut a = call_generic_bound_block(FooType);
+    a = call_generic_bound_block(FooType);
+
+    let mut b = call_where_clause_block(FooType);
+    b = call_where_clause_block(FooType);
+
+    let mut c = call_impl_trait_block(FooType);
+    c = call_impl_trait_block(FooType);
+
+    let f_one = FooType;
+    let f_two = FooType;
+    let mut d = call_with_ref_block(&f_one);
+    d = call_with_ref_block(&f_two);
+}