Adapted to Corrade changes.

Removing of another <*stream> #include leads to more compilation time
saving, now from ~5:12 to ~4:55. Another compilation time improvements
will now be possible only by using Clang's modules, I don't know where
to optimize further (except for getting rid of <sstream> in tests).

src/Math/RectangularMatrix.h

@@ -534,15 +534,19 @@ template<std::size_t cols, std::size_t rows, class T> struct ConfigurationValue<
     /** @brief Reads elements separated with whitespace */
     static Magnum::Math::RectangularMatrix<cols, rows, T> fromString(const std::string& stringValue, ConfigurationValueFlags flags) {
         Magnum::Math::RectangularMatrix<cols, rows, T> result;
-        std::istringstream in(stringValue);
 
-        for(std::size_t row = 0; row != rows; ++row) {
-            for(std::size_t col = 0; col != cols; ++col) {
-                std::string num;
-                in >> num;
-                result(col, row) = ConfigurationValue<T>::fromString(num, flags);
+        std::size_t oldpos = 0, pos = std::string::npos, i = 0;
+        do {
+            pos = stringValue.find(' ', oldpos);
+            std::string part = stringValue.substr(oldpos, pos-oldpos);
+
+            if(!part.empty()) {
+                result(i%cols, i/cols) = ConfigurationValue<T>::fromString(part, flags);
+                ++i;
             }
-        }
+
+            oldpos = pos+1;
+        } while(pos != std::string::npos);
 
         return result;
     }

src/Math/Test/Matrix3Test.cpp

@@ -15,6 +15,7 @@
 
 #include "Matrix3Test.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Constants.h"

src/Math/Test/Matrix4Test.cpp

@@ -15,6 +15,7 @@
 
 #include "Matrix4Test.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Constants.h"

src/Math/Test/MatrixTest.cpp

@@ -15,6 +15,7 @@
 
 #include "MatrixTest.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Matrix.h"

src/Math/Test/Point2DTest.cpp

@@ -15,6 +15,7 @@
 
 #include "Point2DTest.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Point2D.h"

src/Math/Test/Point3DTest.cpp

@@ -15,6 +15,7 @@
 
 #include "Point3DTest.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Point3D.h"

src/Math/Test/RectangularMatrixTest.cpp

@@ -15,6 +15,7 @@
 
 #include "RectangularMatrixTest.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "RectangularMatrix.h"

src/Math/Test/Vector2Test.cpp

@@ -15,6 +15,7 @@
 
 #include "Vector2Test.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Vector2.h"

src/Math/Test/Vector3Test.cpp

@@ -15,6 +15,7 @@
 
 #include "Vector3Test.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Vector3.h"

src/Math/Test/Vector4Test.cpp

@@ -15,6 +15,7 @@
 
 #include "Vector4Test.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Vector4.h"

src/Math/Test/VectorTest.cpp

@@ -15,6 +15,7 @@
 
 #include "VectorTest.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Constants.h"

src/SceneGraph/Test/AnimableTest.cpp

@@ -15,6 +15,8 @@
 
 #include "AnimableTest.h"
 
+#include <sstream>
+
 #include "SceneGraph/Animable.h"
 #include "SceneGraph/AnimableGroup.h"
 #include "SceneGraph/MatrixTransformation3D.h"

src/Test/ColorTest.cpp

@@ -15,6 +15,7 @@
 
 #include "ColorTest.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Color.h"

src/Test/MeshTest.cpp

@@ -15,6 +15,7 @@
 
 #include "MeshTest.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "Mesh.h"

src/Test/TypeTraitsTest.cpp

@@ -15,6 +15,7 @@
 
 #include "TypeTraitsTest.h"
 
+#include <sstream>
 #include <Utility/Configuration.h>
 
 #include "TypeTraits.h"