From ffad636048734fd3a6d38ab003406664476ca158 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Le=C3=B3n=20Orell=20Valerian=20Liehr?= <me@fmease.dev>
Date: Wed, 22 Feb 2023 16:43:52 +0100
Subject: [PATCH] Resolve assoc fns & consts defined on fn ptr tys

---
 compiler/rustc_hir_typeck/src/method/probe.rs |  1 +
 .../associated-item-on-function-pointer.rs    | 34 +++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 tests/ui/associated-item/associated-item-on-function-pointer.rs

diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 8b0473b7454c0..54ff6aeb2f35c 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -692,6 +692,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
             | ty::Slice(_)
             | ty::RawPtr(_)
             | ty::Ref(..)
+            | ty::FnPtr(_)
             | ty::Never
             | ty::Tuple(..) => self.assemble_inherent_candidates_for_incoherent_ty(raw_self_ty),
             _ => {}
diff --git a/tests/ui/associated-item/associated-item-on-function-pointer.rs b/tests/ui/associated-item/associated-item-on-function-pointer.rs
new file mode 100644
index 0000000000000..30ef580df4c0b
--- /dev/null
+++ b/tests/ui/associated-item/associated-item-on-function-pointer.rs
@@ -0,0 +1,34 @@
+// Check that we successfully resolve associated functions and constants defined on
+// function pointer types. Regression test for issue #108270.
+
+// check-pass
+
+#![feature(rustc_attrs)]
+#![rustc_coherence_is_core]
+
+impl fn() {
+    const ARITY: usize = 0;
+
+    fn handle() {}
+
+    fn apply(self) {
+        self()
+    }
+}
+
+impl for<'src> fn(&'src str) -> bool {
+    fn execute(self, source: &'static str) -> bool {
+        self(source)
+    }
+}
+
+fn main() {
+    let _: usize = <fn()>::ARITY;
+    <fn()>::handle();
+
+    let f: fn() = main;
+    f.apply();
+
+    let predicate: fn(&str) -> bool = |source| !source.is_empty();
+    let _ = predicate.execute("...");
+}