tests: extendrtests now tests the extendr-impl block ref/mut Self return

tests/extendrtests/R/extendr-wrappers.R

@@ -196,7 +196,15 @@ MySubmoduleClass$set_a <- function(x) invisible(.Call(wrap__MySubmoduleClass__se
 
 MySubmoduleClass$a <- function() .Call(wrap__MySubmoduleClass__a, self)
 
-MySubmoduleClass$me <- function() .Call(wrap__MySubmoduleClass__me, self)
+MySubmoduleClass$me_owned <- function() .Call(wrap__MySubmoduleClass__me_owned, self)
+
+MySubmoduleClass$me_ref <- function() .Call(wrap__MySubmoduleClass__me_ref, self)
+
+MySubmoduleClass$me_mut <- function() .Call(wrap__MySubmoduleClass__me_mut, self)
+
+MySubmoduleClass$me_explicit_ref <- function() .Call(wrap__MySubmoduleClass__me_explicit_ref, self)
+
+MySubmoduleClass$me_explicit_mut <- function() .Call(wrap__MySubmoduleClass__me_explicit_mut, self)
 
 #' @rdname MySubmoduleClass
 #' @usage NULL

tests/extendrtests/src/rust/src/submodule.rs

@@ -8,7 +8,7 @@ fn hello_submodule() -> &'static str {
 }
 
 // Class for testing
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Clone, Copy)]
 struct MySubmoduleClass {
     a: i32,
 }
@@ -37,13 +37,40 @@ impl MySubmoduleClass {
     fn a(&self) -> i32 {
         self.a
     }
+
+    // NOTE: Cannot move ownership, as that concept is incompatible with bridging
+    // data from R to Rust
+    // fn myself(self) -> Self {
+    //     self
+    // }
 
-    /// Method for getting one's self.
-    fn me(&self) -> &Self {
+    /// Method for getting one's (by way of a copy) self.
+    fn me_owned(&self) -> Self {
+        // only possible due to `derive(Clone, Copy)`
+        *self
+    }
+
+    /// Method for getting one's (ref) self.
+    fn me_ref(&self) -> &Self {
+        self
+    }
+
+    /// Method for getting one's (ref mut) self.
+    fn me_mut(&mut self) -> &mut Self {
         self
     }
-}
 
+    /// Method for getting one's ref (explicit) self.
+    fn me_explicit_ref(&self) -> &MySubmoduleClass {
+        self
+    }
+
+    /// Method for getting one's ref mut (explicit) self.
+    fn me_explicit_mut(&mut self) -> &mut MySubmoduleClass {
+        self
+    }
+}
+
 // Macro to generate exports
 extendr_module! {
     mod submodule;