Allow mocking functions with unknown size type bounds

CHANGELOG.md

@@ -24,6 +24,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   methods, not generic ones.  Among other effects, this prevents "unused method
   expect" warnings from the latest nightly compiler.
   ([#415](https://github.com/asomers/mockall/pull/415))
+- Methods with unknown size type bounds can now be mocked.
+  ([#421](https://github.com/asomers/mockall/pull/421))
 
 ## [ 0.11.2 ] - 2022-07-24
 

mockall/src/lib.rs

@@ -1630,7 +1630,7 @@ pub struct Key(any::TypeId);
 
 #[doc(hidden)]
 impl Key {
-    pub fn new<T: 'static>() -> Self {
+    pub fn new<T: 'static + ?Sized>() -> Self {
         Key(any::TypeId::of::<T>())
     }
 }

mockall/tests/automock_generic_method_with_unknown_size_bounds.rs

@@ -0,0 +1,34 @@
+// vim: tw=80
+//! generic methods with unknown size bounds on their generic parameters
+#![deny(warnings)]
+
+use mockall::*;
+
+#[automock]
+trait Foo {
+    fn foo<T: 'static + ?Sized>(&self, input: Box<T>);
+}
+
+trait Bar {
+    fn get(&self) -> u32;
+}
+
+struct Foobar {
+    value: u32,
+}
+
+impl Bar for Foobar {
+    fn get(&self) -> u32 {
+        self.value
+    }
+}
+
+#[test]
+fn withf() {
+    let mut mock = MockFoo::new();
+    mock.expect_foo::<dyn Bar>()
+        .withf(|x| x.get() == 42)
+        .return_const(());
+
+    mock.foo::<dyn Bar>(Box::new(Foobar { value: 42 }));
+}