Math: creating Vector from one value is broken.

Added "expect fail" test, it is not the priority now (and it is handled
correctly in subclasses).

src/Math/Test/VectorTest.cpp

@@ -30,6 +30,7 @@ class VectorTest: public Corrade::TestSuite::Tester {
 
         void constructFromData();
         void constructDefault();
+        void constructOneValue();
         void constructConversion();
         void data();
 
@@ -66,6 +67,7 @@ typedef Vector<4, std::int32_t> Vector4i;
 VectorTest::VectorTest() {
     addTests(&VectorTest::constructFromData,
              &VectorTest::constructDefault,
+             &VectorTest::constructOneValue,
              &VectorTest::constructConversion,
              &VectorTest::data,
 
@@ -104,6 +106,12 @@ void VectorTest::constructDefault() {
     CORRADE_COMPARE(Vector4(), Vector4(0.0f, 0.0f, 0.0f, 0.0f));
 }
 
+void VectorTest::constructOneValue() {
+    CORRADE_EXPECT_FAIL("Constructing Vector from one value is broken.");
+    CORRADE_VERIFY(false);
+//     CORRADE_COMPARE(Vector4(7.25f), Vector4(7.25f, 7.25f, 7.25f, 7.25f));
+}
+
 void VectorTest::constructConversion() {
     Vector4 floatingPoint(1.3f, 2.7f, -15.0f, 7.0f);
     Vector4 floatingPointRounded(1.0f, 2.0f, -15.0f, 7.0f);

src/Math/Vector.h

@@ -138,7 +138,10 @@ template<std::size_t size, class T> class Vector {
             static_assert(sizeof...(next)+1 == size, "Improper number of arguments passed to Vector constructor");
         }
 
-        /** @brief Construct vector with one value for all fields */
+        /**
+         * @brief Construct vector with one value for all fields
+         * @todo Fix this to be actually usable (not only in subclasses)
+         */
         #ifdef DOXYGEN_GENERATING_OUTPUT
         inline explicit Vector(T value) {
         #else