Work around GCC 4.8 warnings about zero as null pointer constant for {}.

doc/snippets/Magnum.cpp

@@ -104,7 +104,8 @@ Debug{} << "Color of the first pixel is" << image.pixels<Color4ub>()[0][0];
 }
 
 {
-std::nullptr_t data{};
+/* data{} makes GCC 4.8 warn about zero as null pointer constant */
+std::nullptr_t data = nullptr;
 /* [Image-pixels] */
 Image2D image{PixelFormat::RGB8Unorm, {128, 128}, data};
 

src/Magnum/ShaderTools/Test/AbstractConverterTest.cpp

@@ -1451,7 +1451,8 @@ void AbstractConverterTest::linkDataToDataNotImplemented() {
 
     std::ostringstream out;
     Error redirectError{&out};
-    converter.linkDataToData({{}});
+    /* {{}} makes GCC 4.8 warn about zero as null pointer constant */
+    converter.linkDataToData({std::pair<Stage, Containers::ArrayView<const void>>{}});
     CORRADE_COMPARE(out.str(), "ShaderTools::AbstractConverter::linkDataToData(): feature advertised but not implemented\n");
 }
 
@@ -1513,7 +1514,8 @@ void AbstractConverterTest::linkDataToDataCustomDeleter() {
 
     std::ostringstream out;
     Error redirectError{&out};
-    converter.linkDataToData({{}});
+    /* {{}} makes GCC 4.8 warn about zero as null pointer constant */
+    converter.linkDataToData({std::pair<Stage, Containers::ArrayView<const void>>{}});
     CORRADE_COMPARE(out.str(), "ShaderTools::AbstractConverter::linkDataToData(): implementation is not allowed to use a custom Array deleter\n");
 }
 
@@ -1571,7 +1573,8 @@ void AbstractConverterTest::linkDataToFileThroughDataFailed() {
        should be printed (the base implementation assumes the plugin does it) */
     std::ostringstream out;
     Error redirectError{&out};
-    CORRADE_VERIFY(!converter.linkDataToFile({{}}, filename));
+    /* {{}} makes GCC 4.8 warn about zero as null pointer constant */
+    CORRADE_VERIFY(!converter.linkDataToFile({std::pair<Stage, Containers::ArrayView<const void>>{}}, filename));
     CORRADE_VERIFY(!Utility::Directory::exists(filename));
     CORRADE_COMPARE(out.str(), "");
 }
@@ -1591,7 +1594,8 @@ void AbstractConverterTest::linkDataToFileThroughDataNotWritable() {
 
     std::ostringstream out;
     Error redirectError{&out};
-    CORRADE_VERIFY(!converter.linkDataToFile({{}}, "/some/path/that/does/not/exist"));
+    /* {{}} makes GCC 4.8 warn about zero as null pointer constant */
+    CORRADE_VERIFY(!converter.linkDataToFile({std::pair<Stage, Containers::ArrayView<const void>>{}}, "/some/path/that/does/not/exist"));
     CORRADE_COMPARE(out.str(),
         "Utility::Directory::write(): can't open /some/path/that/does/not/exist\n"
         "ShaderTools::AbstractConverter::linkDataToFile(): cannot write to file /some/path/that/does/not/exist\n");
@@ -1631,7 +1635,8 @@ void AbstractConverterTest::linkDataToFileNotImplemented() {
 
     std::ostringstream out;
     Error redirectError{&out};
-    converter.linkDataToFile({{}}, "file.dat");
+    /* {{}} makes GCC 4.8 warn about zero as null pointer constant */
+    converter.linkDataToFile({std::pair<Stage, Containers::ArrayView<const void>>{}}, "file.dat");
     CORRADE_COMPARE(out.str(), "ShaderTools::AbstractConverter::linkDataToData(): feature advertised but not implemented\n");
 }
 
@@ -1850,7 +1855,8 @@ void AbstractConverterTest::linkFilesToFileNotImplemented() {
 
     std::ostringstream out;
     Error redirectError{&out};
-    converter.linkFilesToFile({{}}, {});
+    /* {{}} makes GCC 4.8 warn about zero as null pointer constant */
+    converter.linkFilesToFile({std::pair<Stage, Containers::StringView>{}}, {});
     CORRADE_COMPARE(out.str(), "ShaderTools::AbstractConverter::linkFilesToFile(): feature advertised but not implemented\n");
 }
 

src/Magnum/Shaders/Test/PhongGLTest.cpp

@@ -1502,7 +1502,8 @@ void PhongGLTest::setSpecularDisabled() {
     PhongGL shader{PhongGL::Flag::NoSpecular};
     shader.setSpecularColor({})
         .setShininess({})
-        .setLightSpecularColors({{}})
+        /* {{}} makes GCC 4.8 warn about zero as null pointer constant */
+        .setLightSpecularColors({Color3{}})
         .setLightSpecularColor(0, {});
     CORRADE_COMPARE(out.str(),
         "Shaders::PhongGL::setSpecularColor(): the shader was created with specular disabled\n"