Don't return reference on copy assignment operators

We prefer to prevent using chained assignment (`T a = b = c = T();`) as this
can lead to confusing code and subtle bugs.

According to https://en.wikipedia.org/wiki/Assignment_operator_(C%2B%2B), C++
allows any arbitrary return type, so this is standard compliant.

This could be re-assessed if/when we have an actual need for a behavior more
akin to that of the C++ STL, for now this PR simply changes a handful of
cases which were inconsistent with the rest of the codebase (`void` return
type was already the most common case prior to this commit).

2 files changed, 2 insertions, 4 deletions

diff --git a/core/math/audio_frame.h b/core/math/audio_frame.h
index a5616b8d79..4a11b99fe8 100644
--- a/core/math/audio_frame.h
+++ b/core/math/audio_frame.h
@@ -124,10 +124,9 @@ struct AudioFrame {
 		r = p_frame.r;
 	}
 
-	_ALWAYS_INLINE_ AudioFrame &operator=(const AudioFrame &p_frame) {
+	_ALWAYS_INLINE_ void operator=(const AudioFrame &p_frame) {
 		l = p_frame.l;
 		r = p_frame.r;
-		return *this;
 	}
 
 	_ALWAYS_INLINE_ operator Vector2() const {
diff --git a/core/math/quaternion.h b/core/math/quaternion.h
index d8d0c06672..457d167516 100644
--- a/core/math/quaternion.h
+++ b/core/math/quaternion.h
@@ -134,12 +134,11 @@ public:
 			w(p_q.w) {
 	}
 
-	Quaternion &operator=(const Quaternion &p_q) {
+	void operator=(const Quaternion &p_q) {
 		x = p_q.x;
 		y = p_q.y;
 		z = p_q.z;
 		w = p_q.w;
-		return *this;
 	}
 
 	Quaternion(const Vector3 &v0, const Vector3 &v1) // shortest arc