feat: ide-assist, generate blanket trait impl

crates/ide-assists/src/lib.rs

@@ -152,6 +152,7 @@ mod handlers {
     mod flip_comma;
     mod flip_or_pattern;
     mod flip_trait_bound;
+    mod generate_blanket_trait_impl;
     mod generate_constant;
     mod generate_default_from_enum_variant;
     mod generate_default_from_new;
@@ -288,6 +289,7 @@ mod handlers {
             generate_default_from_enum_variant::generate_default_from_enum_variant,
             generate_default_from_new::generate_default_from_new,
             generate_delegate_trait::generate_delegate_trait,
+            generate_blanket_trait_impl::generate_blanket_trait_impl,
             generate_derive::generate_derive,
             generate_documentation_template::generate_doc_example,
             generate_documentation_template::generate_documentation_template,

crates/ide-assists/src/tests/generated.rs

@@ -1270,6 +1270,46 @@ fn foo<T: Copy + Clone>() { }
     )
 }
 
+#[test]
+fn doctest_generate_blanket_trait_impl() {
+    check_doc_test(
+        "generate_blanket_trait_impl",
+        r#####"
+trait $0Foo<T: Send>: ToOwned
+where
+    Self::Owned: Default,
+{
+    fn foo(&self) -> T;
+
+    fn print_foo(&self) {
+        println!("{}", self.foo());
+    }
+}
+"#####,
+        r#####"
+trait Foo<T: Send>: ToOwned
+where
+    Self::Owned: Default,
+{
+    fn foo(&self) -> T;
+
+    fn print_foo(&self) {
+        println!("{}", self.foo());
+    }
+}
+
+$0impl<T: Send, This: ToOwned> Foo<T> for This
+where
+    Self::Owned: Default,
+{
+    fn foo(&self) -> T {
+        todo!()
+    }
+}
+"#####,
+    )
+}
+
 #[test]
 fn doctest_generate_constant() {
     check_doc_test(

crates/ide-assists/src/utils.rs

@@ -747,16 +747,23 @@ fn generate_impl_inner(
     .clone_for_update();
 
     // Copy any cfg attrs from the original adt
-    let cfg_attrs = adt
-        .attrs()
-        .filter(|attr| attr.as_simple_call().map(|(name, _arg)| name == "cfg").unwrap_or(false));
-    for attr in cfg_attrs {
-        impl_.add_attr(attr.clone_for_update());
-    }
+    add_cfg_attrs_to(adt, &impl_);
 
     impl_
 }
 
+pub(crate) fn add_cfg_attrs_to<T, U>(from: &T, to: &U)
+where
+    T: HasAttrs,
+    U: AttrsOwnerEdit,
+{
+    let cfg_attrs =
+        from.attrs().filter(|attr| attr.as_simple_call().is_some_and(|(name, _arg)| name == "cfg"));
+    for attr in cfg_attrs {
+        to.add_attr(attr.clone_for_update());
+    }
+}
+
 pub(crate) fn add_method_to_adt(
     builder: &mut SourceChangeBuilder,
     adt: &ast::Adt,