Temp (#123)

* Coverage

* added fixes

* removed spacing

* removed junk

* removed print

* removed coverage

* removed useless stuff

* fix

---------

Co-authored-by: Saikari <lin@sz.cn.eu.org>

tests/general/unit_test_linear_algebra_cover_remaining.cpp

@@ -0,0 +1,52 @@
+// Additional coverage tests for Vector4 and Mat
+#include <gtest/gtest.h>
+#include <stdexcept>
+
+#include "omath/linear_algebra/vector4.hpp"
+#include "omath/linear_algebra/mat.hpp"
+
+using namespace omath;
+
+static void make_bad_mat_rows()
+{
+    // wrong number of rows -> should throw inside initializer-list ctor
+    Mat<2, 2, float> m{{1.f, 2.f}};
+    (void)m;
+}
+
+static void make_bad_mat_cols()
+{
+    // row with wrong number of columns -> should throw
+    Mat<2, 2, float> m{{1.f, 2.f}, {1.f}};
+    (void)m;
+}
+
+TEST(Vector4Operator, Subtraction)
+{
+    Vector4<float> a{5.f, 6.f, 7.f, 8.f};
+    Vector4<float> b{1.f, 2.f, 3.f, 4.f};
+
+    auto r = a - b;
+    EXPECT_FLOAT_EQ(r.x, 4.f);
+    EXPECT_FLOAT_EQ(r.y, 4.f);
+    EXPECT_FLOAT_EQ(r.z, 4.f);
+    EXPECT_FLOAT_EQ(r.w, 4.f);
+}
+
+TEST(MatInitializerExceptions, ForcedThrowLines)
+{
+    EXPECT_THROW(make_bad_mat_rows(), std::invalid_argument);
+    EXPECT_THROW(make_bad_mat_cols(), std::invalid_argument);
+}
+
+TEST(MatSelfAssignment, CopyAndMoveSelfAssign)
+{
+    Mat<2,2,float> m{{1.f,2.f},{3.f,4.f}};
+    // self copy-assignment
+    m = m;
+    EXPECT_FLOAT_EQ(m.at(0, 0), 1.f);
+
+    // self move-assignment
+    m = std::move(m);
+    EXPECT_FLOAT_EQ(m.at(0, 0), 1.f);
+}