GCC 11, your fancy new warnings are NOT helpful.

doc/snippets/MagnumGL.cpp

@@ -121,7 +121,15 @@ carBumpTexture.setStorage(5, GL::TextureFormat::RGB8, {256, 256})
 #endif
 
 {
+#if defined(CORRADE_TARGET_GCC) && __GNUC__ >= 11
+#pragma GCC diagnostic push
+/* Stupid thing. YES I WANT THIS TO BE A FUNCTION, CAN YOU SHUT UP */
+#pragma GCC diagnostic ignored "-Wvexing-parse"
+#endif
 auto importSomeMesh() -> std::tuple<GL::Mesh, GL::Buffer, GL::Buffer>;
+#if defined(CORRADE_TARGET_GCC) && __GNUC__ >= 11
+#pragma GCC diagnostic pop
+#endif
 /* [opengl-wrapping-nocreate] */
 GL::Mesh mesh{NoCreate};
 GL::Buffer vertices{NoCreate}, indices{NoCreate};

doc/snippets/MagnumMath.cpp

@@ -625,6 +625,11 @@ static_cast<void>(radians);
 }
 
 {
+#if defined(CORRADE_TARGET_GCC) && __GNUC__ >= 11
+#pragma GCC diagnostic push
+/* Stupid thing. YES I WANT THIS TO BE A FUNCTION, CAN YOU SHUT UP */
+#pragma GCC diagnostic ignored "-Wvexing-parse"
+#endif
 /* [Deg-usage-convert] */
 Double foo();
 
@@ -634,6 +639,9 @@ Radd radians{foo()};
 /* [Deg-usage-convert] */
 static_cast<void>(degrees);
 static_cast<void>(radians);
+#if defined(CORRADE_TARGET_GCC) && __GNUC__ >= 11
+#pragma GCC diagnostic pop
+#endif
 }
 
 {
@@ -646,6 +654,11 @@ static_cast<void>(b);
 }
 
 {
+#if defined(CORRADE_TARGET_GCC) && __GNUC__ >= 11
+#pragma GCC diagnostic push
+/* Stupid thing. YES I WANT THIS TO BE A FUNCTION, CAN YOU SHUT UP */
+#pragma GCC diagnostic ignored "-Wvexing-parse"
+#endif
 Double foo();
 /* [Deg-usage-comparison] */
 Rad angle();
@@ -654,6 +667,9 @@ Deg x = angle();                // convert to degrees for easier comparison
 if(x < 30.0_degf) foo();
 //if(x > 1.57_radf) bar();      // error, both need to be of the same type
 /* [Deg-usage-comparison] */
+#if defined(CORRADE_TARGET_GCC) && __GNUC__ >= 11
+#pragma GCC diagnostic pop
+#endif
 }
 
 {

src/Magnum/Trade/Test/MeshDataTest.cpp

@@ -1552,8 +1552,8 @@ void MeshDataTest::constructAttributelessNotOwned() {
 }
 
 void MeshDataTest::constructIndexlessAttributeless() {
-    int importerState;
-    MeshData data{MeshPrimitive::TriangleStrip, 37, &importerState};
+    int state{}; /* GCC 11 complains that "maybe uninitialized" w/o the {} */
+    MeshData data{MeshPrimitive::TriangleStrip, 37, &state};
     /* These are both empty so it doesn't matter, but this is a nice
        non-restrictive default */
     CORRADE_COMPARE(data.indexDataFlags(), DataFlag::Owned|DataFlag::Mutable);
@@ -1562,7 +1562,7 @@ void MeshDataTest::constructIndexlessAttributeless() {
     CORRADE_VERIFY(!data.attributeData());
     CORRADE_COMPARE(data.indexData(), nullptr);
     CORRADE_COMPARE(data.vertexData(), nullptr);
-    CORRADE_COMPARE(data.importerState(), &importerState);
+    CORRADE_COMPARE(data.importerState(), &state);
 
     CORRADE_VERIFY(!data.isIndexed());
     CORRADE_COMPARE(data.vertexCount(), 37);
@@ -1570,13 +1570,13 @@ void MeshDataTest::constructIndexlessAttributeless() {
 }
 
 void MeshDataTest::constructIndexlessAttributelessZeroVertices() {
-    int importerState;
-    MeshData data{MeshPrimitive::TriangleStrip, 0, &importerState};
+    int state{}; /* GCC 11 complains that "maybe uninitialized" w/o the {} */
+    MeshData data{MeshPrimitive::TriangleStrip, 0, &state};
     CORRADE_COMPARE(data.primitive(), MeshPrimitive::TriangleStrip);
     CORRADE_VERIFY(!data.attributeData());
     CORRADE_COMPARE(data.indexData(), nullptr);
     CORRADE_COMPARE(data.vertexData(), nullptr);
-    CORRADE_COMPARE(data.importerState(), &importerState);
+    CORRADE_COMPARE(data.importerState(), &state);
 
     CORRADE_VERIFY(!data.isIndexed());
     CORRADE_COMPARE(data.vertexCount(), 0);

src/Magnum/Trade/Test/SkinDataTest.cpp

@@ -56,7 +56,7 @@ SkinDataTest::SkinDataTest() {
 }
 
 void SkinDataTest::construct() {
-    int state;
+    int state{}; /* GCC 11 complains that "maybe uninitialized" w/o the {} */
     SkinData3D data{{0, 2, 3}, {
         Matrix4::translation(Vector3::zAxis(0.0f)),
         Matrix4::translation(Vector3::zAxis(2.0f)),
@@ -102,7 +102,7 @@ void SkinDataTest::constructCopy() {
 }
 
 void SkinDataTest::constructMove() {
-    int state;
+    int state{}; /* GCC 11 complains that "maybe uninitialized" w/o the {} */
     SkinData3D a{{0, 2, 3}, {
         Matrix4::translation(Vector3::zAxis(0.0f)),
         Matrix4::translation(Vector3::zAxis(2.0f)),