Trying out qmetaobject-rs method for docs.

src/lib.rs

@@ -39,10 +39,29 @@
 //!   engine.exec();
 //! }
 //! ```
+use qmetaobject::prelude::*;
 use std::ffi::c_void;
 
+#[cfg(not(no_qt))]
 use cpp::{cpp, cpp_class};
-use qmetaobject::prelude::*;
+
+#[cfg(no_qt)]
+mod no_qt {
+    pub fn panic<T>() -> T {
+        panic!("This example is not supported on Qt 6 and above")
+    }
+}
+
+#[cfg(no_qt)]
+macro_rules! cpp {
+    {{ $($t:tt)* }} => {};
+    {$(unsafe)? [$($a:tt)*] -> $ret:ty as $b:tt { $($t:tt)* } } => {
+        crate::no_qt::panic::<$ret>()
+    };
+    { $($t:tt)* } => {
+        crate::no_qt::panic::<()>()
+    };
+}
 
 cpp! {{
     #include <KLocalizedContext>