From 35c948ff4a36b9c031bda96f79b8bf9e0d5bda26 Mon Sep 17 00:00:00 2001
From: Florian Diebold <flodiebold@gmail.com>
Date: Tue, 25 May 2021 14:24:08 +0200
Subject: Fix lowering of FnOnce() without return type
This should result in an implicit `-> ()`, not leaving out the binding.
---
crates/hir_ty/src/tests/traits.rs | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)
(limited to 'crates/hir_ty/src/tests')
diff --git a/crates/hir_ty/src/tests/traits.rs b/crates/hir_ty/src/tests/traits.rs
index a5a2df54c..714f12937 100644
--- a/crates/hir_ty/src/tests/traits.rs
+++ b/crates/hir_ty/src/tests/traits.rs
@@ -3041,7 +3041,7 @@ fn infer_fn_trait_arg() {
#[test]
fn infer_box_fn_arg() {
- // The type mismatch is a bug
+ // The type mismatch is because we don't define Unsize and CoerceUnsized
check_infer_with_mismatches(
r#"
//- /lib.rs deps:std
@@ -3095,16 +3095,16 @@ fn foo() {
478..576 '{ ...&s); }': ()
488..489 's': Option<i32>
492..504 'Option::None': Option<i32>
- 514..515 'f': Box<dyn FnOnce(&Option<i32>)>
+ 514..515 'f': Box<dyn FnOnce(&Option<i32>) -> ()>
549..562 'box (|ps| {})': Box<|{unknown}| -> ()>
554..561 '|ps| {}': |{unknown}| -> ()
555..557 'ps': {unknown}
559..561 '{}': ()
- 568..569 'f': Box<dyn FnOnce(&Option<i32>)>
- 568..573 'f(&s)': FnOnce::Output<dyn FnOnce(&Option<i32>), (&Option<i32>,)>
+ 568..569 'f': Box<dyn FnOnce(&Option<i32>) -> ()>
+ 568..573 'f(&s)': ()
570..572 '&s': &Option<i32>
571..572 's': Option<i32>
- 549..562: expected Box<dyn FnOnce(&Option<i32>)>, got Box<|{unknown}| -> ()>
+ 549..562: expected Box<dyn FnOnce(&Option<i32>) -> ()>, got Box<|{unknown}| -> ()>
"#]],
);
}
@@ -3571,3 +3571,25 @@ fn main() {
"#]],
)
}
+
+#[test]
+fn fn_returning_unit() {
+ check_infer_with_mismatches(
+ r#"
+#[lang = "fn_once"]
+trait FnOnce<Args> {
+ type Output;
+}
+
+fn test<F: FnOnce()>(f: F) {
+ let _: () = f();
+}"#,
+ expect![[r#"
+ 82..83 'f': F
+ 88..112 '{ ...f(); }': ()
+ 98..99 '_': ()
+ 106..107 'f': F
+ 106..109 'f()': ()
+ "#]],
+ );
+}
--
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