Be nice and provide a clear assert in meshIndexTypeSize().

src/Magnum/CMakeLists.txt

@@ -29,7 +29,6 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/configure.h.cmake
 # Files shared between main library and unit test library
 set(Magnum_SRCS
     FileCallback.cpp
-    Mesh.cpp
     PixelStorage.cpp
     Resource.cpp
     Sampler.cpp
@@ -38,6 +37,7 @@ set(Magnum_SRCS
 set(Magnum_GracefulAssert_SRCS
     Image.cpp
     ImageView.cpp
+    Mesh.cpp
     PixelFormat.cpp
 
     Animation/Player.cpp

src/Magnum/Mesh.cpp

@@ -39,7 +39,7 @@ UnsignedInt meshIndexTypeSize(MeshIndexType type) {
         case MeshIndexType::UnsignedInt: return 4;
     }
 
-    CORRADE_ASSERT_UNREACHABLE(); /* LCOV_EXCL_LINE */
+    CORRADE_ASSERT(false, "meshIndexTypeSize(): invalid type" << type, {});
 }
 
 #ifndef DOXYGEN_GENERATING_OUTPUT

src/Magnum/Test/CMakeLists.txt

@@ -27,7 +27,7 @@ corrade_add_test(ArrayTest ArrayTest.cpp LIBRARIES Magnum)
 corrade_add_test(FileCallbackTest FileCallbackTest.cpp LIBRARIES Magnum)
 corrade_add_test(ImageTest ImageTest.cpp LIBRARIES MagnumTestLib)
 corrade_add_test(ImageViewTest ImageViewTest.cpp LIBRARIES MagnumTestLib)
-corrade_add_test(MeshTest MeshTest.cpp LIBRARIES Magnum)
+corrade_add_test(MeshTest MeshTest.cpp LIBRARIES MagnumTestLib)
 corrade_add_test(PixelFormatTest PixelFormatTest.cpp LIBRARIES MagnumTestLib)
 target_compile_definitions(PixelFormatTest PRIVATE "CORRADE_GRACEFUL_ASSERT")
 corrade_add_test(PixelStorageTest PixelStorageTest.cpp LIBRARIES Magnum)

src/Magnum/Test/MeshTest.cpp

@@ -39,6 +39,7 @@ struct MeshTest: TestSuite::Tester {
     void indexTypeMapping();
 
     void indexTypeSize();
+    void indexTypeSizeInvalid();
 
     void debugPrimitive();
     void debugIndexType();
@@ -51,6 +52,7 @@ MeshTest::MeshTest() {
               &MeshTest::indexTypeMapping,
 
               &MeshTest::indexTypeSize,
+              &MeshTest::indexTypeSizeInvalid,
 
               &MeshTest::debugPrimitive,
               &MeshTest::debugIndexType,
@@ -138,6 +140,15 @@ void MeshTest::indexTypeSize() {
     CORRADE_COMPARE(meshIndexTypeSize(MeshIndexType::UnsignedInt), 4);
 }
 
+void MeshTest::indexTypeSizeInvalid() {
+    std::ostringstream out;
+    Error redirectError{&out};
+
+    meshIndexTypeSize(MeshIndexType(0xdead));
+
+    CORRADE_COMPARE(out.str(), "meshIndexTypeSize(): invalid type MeshIndexType(0xdead)\n");
+}
+
 void MeshTest::debugPrimitive() {
     std::ostringstream o;
     Debug(&o) << MeshPrimitive::TriangleFan << MeshPrimitive(0xdead);