Oops. Bug

msg_gen/src/lib.rs

@@ -211,13 +211,20 @@ fn untyped_serialize_helper(typename: &str) -> Result<fn(json: serde_json::Value
     }
     se_helper.push_str(&format!("return Err(())\n}}"));
 
+    let mut alloc_helper = format!("fn untyped_alloc_helper(typename: &str) -> Result<*mut std::os::raw::c_void, ()> {{");
+    for msg in msgs {
+        alloc_helper.push_str(&generate_untyped_alloc_helper(&msg.module, &msg.prefix, &msg.name));
+    }
+    alloc_helper.push_str(&format!("return Err(())\n}}"));
+
+
     let mut dealloc_helper = format!("fn untyped_dealloc_helper(typename: &str) -> Result<fn(*mut std::os::raw::c_void), ()> {{");
     for msg in msgs {
         dealloc_helper.push_str(&generate_untyped_dealloc_helper(&msg.module, &msg.prefix, &msg.name));
     }
     dealloc_helper.push_str(&format!("return Err(())\n}}"));
 
-    format!("{} \n\n {} \n\n {} \n\n {} \n\n", ts_helper, ds_helper, se_helper, dealloc_helper)
+    format!("{} \n\n {} \n\n {} \n\n {} \n\n {} \n\n", ts_helper, ds_helper, se_helper, alloc_helper, dealloc_helper)
 }
 
 
@@ -268,6 +275,19 @@ pub fn generate_untyped_serialize_helper(module_: &str, prefix_: &str, name_: &s
     }}", typename = typename, rustname = rustname)
 }
 
+
+pub fn generate_untyped_alloc_helper(module_: &str, prefix_: &str, name_: &str) -> String {
+    let typename = format!("{}/{}/{}", module_, prefix_, name_);
+    let rustname = format!("{}::{}::{}", module_, prefix_, name_);
+
+    format!("
+    if typename == \"{typename}\" {{
+        return Ok({rustname}::create_msg() as *mut std::os::raw::c_void);
+    }}
+", typename = typename, rustname = rustname)
+}
+
+
 pub fn generate_untyped_dealloc_helper(module_: &str, prefix_: &str, name_: &str) -> String {
     let typename = format!("{}/{}/{}", module_, prefix_, name_);
     let rustname = format!("{}::{}::{}", module_, prefix_, name_);

src/lib.rs

@@ -112,6 +112,7 @@ struct WrappedSubUntyped {
     rcl_handle: rcl_subscription_t,
     callback: Box<dyn FnMut(serde_json::Value) -> ()>,
     serialize: Box<dyn FnMut(*const std::os::raw::c_void) -> serde_json::Value>,
+    dealloc: Box<dyn FnMut(*mut std::os::raw::c_void) -> ()>,
     rcl_msg: *mut std::os::raw::c_void,
 }
 
@@ -184,6 +185,7 @@ impl Sub for WrappedSubUntyped
         unsafe {
             rcl_subscription_fini(&mut self.rcl_handle, node);
         }
+        (self.dealloc)(self.rcl_msg); // manually delete message
     }
 }
 
@@ -386,12 +388,14 @@ impl Node {
         let ts = untyped_ts_helper(topic_type)?;
         let de = untyped_deserialize_helper(topic_type)?;
         let subscription_handle = self.create_subscription_helper(topic, ts)?;
+        let dealloc = untyped_dealloc_helper(topic_type)?;
 
         let ws = WrappedSubUntyped {
             rcl_handle: subscription_handle,
-            rcl_msg: unsafe { std_msgs__msg__String__create() as *mut _ as *mut std::os::raw::c_void },
+            rcl_msg: untyped_alloc_helper(topic_type)?,
             callback: callback,
             serialize: Box::new(de),
+            dealloc: Box::new(dealloc),
         };
         self.subs.push(Box::new(ws));
         Ok(self.subs.last().unwrap().handle()) // hmm...