Any{Image,Scene}{Importer,Converter}: improve plugin checks in tests.

These checks covered the case when the magnum-plugins repository wasn't
installed, but didn't cover the case when it was installed but the
plugins were built against an outdated interface, had ABI issues, or
didn't load at all for various other reasons.

src/MagnumPlugins/AnyImageConverter/Test/AnyImageConverterTest.cpp

@@ -429,7 +429,8 @@ void AnyImageConverterTest::convert1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "1d.ktx2");
@@ -466,7 +467,8 @@ void AnyImageConverterTest::convert3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "3d.ktx2");
@@ -488,7 +490,8 @@ void AnyImageConverterTest::convertCompressed1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-1d.ktx2");
@@ -508,7 +511,8 @@ void AnyImageConverterTest::convertCompressed2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-2d.ktx2");
@@ -528,7 +532,8 @@ void AnyImageConverterTest::convertCompressed3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-3d.ktx2");
@@ -548,7 +553,8 @@ void AnyImageConverterTest::convertLevels1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "levels-1d.ktx2");
@@ -570,7 +576,8 @@ void AnyImageConverterTest::convertLevels2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "levels-2d.ktx2");
@@ -592,7 +599,8 @@ void AnyImageConverterTest::convertLevels3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "levels-3d.ktx2");
@@ -614,7 +622,8 @@ void AnyImageConverterTest::convertCompressedLevels1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-levels-1d.ktx2");
@@ -636,7 +645,8 @@ void AnyImageConverterTest::convertCompressedLevels2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-levels-2d.ktx2");
@@ -658,7 +668,8 @@ void AnyImageConverterTest::convertCompressedLevels3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-levels-3d.ktx2");
@@ -1085,7 +1096,8 @@ void AnyImageConverterTest::propagateFlags3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("OpenExrImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("OpenExrImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("OpenExrImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "cube.exr");
@@ -1141,7 +1153,8 @@ void AnyImageConverterTest::propagateFlagsLevels2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("OpenExrImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("OpenExrImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("OpenExrImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "output.exr");
@@ -1182,7 +1195,8 @@ void AnyImageConverterTest::propagateFlagsLevels3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("OpenExrImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("OpenExrImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("OpenExrImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "cube.exr");
@@ -1236,7 +1250,8 @@ void AnyImageConverterTest::propagateConfiguration1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "custom-writer-1d.ktx2");
@@ -1258,7 +1273,8 @@ void AnyImageConverterTest::propagateConfiguration2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("OpenExrImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("OpenExrImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("OpenExrImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "depth32f-custom-channels.exr");
@@ -1282,7 +1298,8 @@ void AnyImageConverterTest::propagateConfiguration3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "custom-writer-3d.ktx2");
@@ -1304,7 +1321,8 @@ void AnyImageConverterTest::propagateConfigurationUnknown1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1335,7 +1353,8 @@ void AnyImageConverterTest::propagateConfigurationUnknown3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1353,7 +1372,8 @@ void AnyImageConverterTest::propagateConfigurationCompressed1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-custom-writer-1d.ktx2");
@@ -1375,7 +1395,8 @@ void AnyImageConverterTest::propagateConfigurationCompressed2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-custom-writer-2d.ktx2");
@@ -1397,7 +1418,8 @@ void AnyImageConverterTest::propagateConfigurationCompressed3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-custom-writer-3d.ktx2");
@@ -1419,7 +1441,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedUnknown1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1437,7 +1460,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedUnknown2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1455,7 +1479,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedUnknown3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1473,7 +1498,8 @@ void AnyImageConverterTest::propagateConfigurationLevels1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "custom-writer-1d.ktx2");
@@ -1497,7 +1523,8 @@ void AnyImageConverterTest::propagateConfigurationLevels2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "custom-writer-2d.ktx2");
@@ -1521,7 +1548,8 @@ void AnyImageConverterTest::propagateConfigurationLevels3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "custom-writer-3d.ktx2");
@@ -1545,7 +1573,8 @@ void AnyImageConverterTest::propagateConfigurationUnknownLevels1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1565,7 +1594,8 @@ void AnyImageConverterTest::propagateConfigurationUnknownLevels2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1585,7 +1615,8 @@ void AnyImageConverterTest::propagateConfigurationUnknownLevels3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1605,7 +1636,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedLevels1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-custom-writer-1d.ktx2");
@@ -1629,7 +1661,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedLevels2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compressed-custom-writer-2d.ktx2");
@@ -1653,7 +1686,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedLevels3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYIMAGECONVERTER_TEST_OUTPUT_DIR, "compresed-custom-writer-3d.ktx2");
@@ -1677,7 +1711,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedUnknownLevels1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1697,7 +1732,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedUnknownLevels2D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");
@@ -1717,7 +1753,8 @@ void AnyImageConverterTest::propagateConfigurationCompressedUnknownLevels3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImageConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImageConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImageConverter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImageConverter> converter = manager.instantiate("AnyImageConverter");

src/MagnumPlugins/AnyImageImporter/Test/AnyImageImporterTest.cpp

@@ -207,7 +207,8 @@ void AnyImageImporterTest::load1D() {
     CORRADE_VERIFY(manager.load(ANYIMAGEIMPORTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImporter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImporter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImporter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImporter> importer = manager.instantiate("AnyImageImporter");
@@ -257,7 +258,8 @@ void AnyImageImporterTest::load3D() {
     CORRADE_VERIFY(manager.load(ANYIMAGEIMPORTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("KtxImporter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("KtxImporter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("KtxImporter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImporter> importer = manager.instantiate("AnyImageImporter");
@@ -363,7 +365,8 @@ void AnyImageImporterTest::propagateConfiguration() {
     CORRADE_VERIFY(manager.load(ANYIMAGEIMPORTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("OpenExrImporter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("OpenExrImporter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("OpenExrImporter plugin can't be loaded.");
 
     Containers::Pointer<AbstractImporter> importer = manager.instantiate("AnyImageImporter");

src/MagnumPlugins/AnySceneConverter/Test/AnySceneConverterTest.cpp

@@ -97,7 +97,8 @@ void AnySceneConverterTest::convert() {
     CORRADE_VERIFY(manager.load(ANYSCENECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("StanfordSceneConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("StanfordSceneConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("StanfordSceneConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYSCENECONVERTER_TEST_OUTPUT_DIR, "file.ply");
@@ -156,7 +157,8 @@ void AnySceneConverterTest::propagateFlags() {
     CORRADE_VERIFY(manager.load(ANYSCENECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("StanfordSceneConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("StanfordSceneConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("StanfordSceneConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYSCENECONVERTER_TEST_OUTPUT_DIR, "file.ply");
@@ -193,7 +195,8 @@ void AnySceneConverterTest::propagateConfiguration() {
     CORRADE_VERIFY(manager.load(ANYSCENECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("StanfordSceneConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("StanfordSceneConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("StanfordSceneConverter plugin can't be loaded.");
 
     const std::string filename = Utility::Directory::join(ANYSCENECONVERTER_TEST_OUTPUT_DIR, "file.ply");
@@ -225,7 +228,8 @@ void AnySceneConverterTest::propagateConfigurationUnknown() {
     CORRADE_VERIFY(manager.load(ANYSCENECONVERTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
     #endif
 
-    if(manager.loadState("StanfordSceneConverter") < PluginManager::LoadState::Loaded)
+    /* Catch also ABI and interface mismatch errors */
+    if(!(manager.load("StanfordSceneConverter") & PluginManager::LoadState::Loaded))
         CORRADE_SKIP("StanfordSceneConverter plugin can't be loaded.");
 
     const Vector3 positions[] {