Merge pull request #1110 from bsilver8192/subclass-std

Fix and test subclasses with C++ std in scope

engine/src/conversion/codegen_rs/mod.rs

@@ -831,7 +831,7 @@ impl<'a> RsCodeGenerator<'a> {
                         .as_ref()
                         .#borrow()
                         .expect(#reentrancy_panic_msg);
-                    let r = std::ops::#deref_ty::#deref_call(& #mut_token b);
+                    let r = ::std::ops::#deref_ty::#deref_call(& #mut_token b);
                     #methods_trait :: #method_name
                         (r,
                         #args)

integration-tests/tests/integration_test.rs

@@ -7587,6 +7587,49 @@ fn test_non_pv_subclass_simple() {
     );
 }
 
+#[test]
+/// Tests the Rust code generated for subclasses when there's a `std` module in scope representing
+/// the C++ `std` namespace. This breaks if any of the generated Rust code fails to fully qualify
+/// its references to the Rust `std`.
+fn test_subclass_with_std() {
+    let hdr = indoc! {"
+    #include <cstdint>
+    #include <chrono>
+
+    class Observer {
+    public:
+        Observer() {}
+        virtual void foo() const {}
+        virtual ~Observer() {}
+
+        void unused(std::chrono::nanoseconds) {}
+    };
+    "};
+    run_test_ex(
+        "",
+        hdr,
+        quote! {
+            let obs = MyObserver::new_rust_owned(MyObserver { a: 3, cpp_peer: Default::default() });
+            obs.borrow().foo();
+        },
+        quote! {
+            subclass!("Observer",MyObserver)
+        },
+        None,
+        None,
+        Some(quote! {
+            use autocxx::subclass::CppSubclass;
+            use ffi::Observer_methods;
+            #[autocxx::subclass::subclass]
+            pub struct MyObserver {
+                a: u32
+            }
+            impl Observer_methods for MyObserver {
+            }
+        }),
+    );
+}
+
 #[test]
 fn test_two_subclasses() {
     let hdr = indoc! {"