Implement PartialEq for QVariant (#490)

This fixes #[qproperty] not being available for QVariant, because the
generated setter would use the equality operator.

Fixes #487

Author: vimpostor

CHANGELOG.md

@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - `qrc` resources added to `CxxQtBuilder` or `QtBuild` now trigger `cargo:rerun-if-changed` for file entries
+- Fix not being able to use `QVariant` as a `#[qproperty]`, because the `PartialEq` implementation was missing
 
 ## [0.5.0](https://github.com/KDAB/cxx-qt/compare/v0.4.1...v0.5.0) - 2023-03-08
 

crates/cxx-qt-lib/src/core/qvariant/mod.rs

@@ -35,6 +35,9 @@ mod ffi {
         #[doc(hidden)]
         #[rust_name = "qvariant_clone"]
         fn construct(variant: &QVariant) -> QVariant;
+        #[doc(hidden)]
+        #[rust_name = "qvariant_eq"]
+        fn operatorEq(a: &QVariant, b: &QVariant) -> bool;
     }
 }
 
@@ -121,6 +124,12 @@ impl QVariant {
     }
 }
 
+impl std::cmp::PartialEq for QVariant {
+    fn eq(&self, other: &Self) -> bool {
+        ffi::qvariant_eq(self, other)
+    }
+}
+
 pub trait QVariantValue {
     fn can_convert(variant: &QVariant) -> bool;
     fn construct(value: &Self) -> QVariant;