Use actual epsilon

vector_test.cpp

@@ -132,18 +132,18 @@ TEST(Vector, DivisionWorksAcrossTypes) {
 TEST(Vector, Length) {
   //    EXPECT_THAT(iota3i().lengthSquared(), 14);
   EXPECT_THAT(iota3i().magnitude(),
-              ::testing::DoubleNear(std::sqrt(14), 0.00001));
+              ::testing::DoubleNear(std::sqrt(14),  std::numeric_limits<double>::epsilon()));
 }
 
 TEST(Vector, Distance) {
   //    EXPECT_THAT((iota3i().distanceSquared(vec3i{3, 1, -1})), 21);
   EXPECT_THAT((iota3i() - vec3i({3, 1, -1})).magnitude(),
-              ::testing::DoubleNear(std::sqrt(21), 0.00001));
+              ::testing::DoubleNear(std::sqrt(21),  std::numeric_limits<double>::epsilon()));
 }
 
 TEST(Vector, Projection) {
   EXPECT_THAT(iota3i().projection(vec3i({3, 1, -1})).magnitude(),
-              ::testing::DoubleNear(std::sqrt(4.0/11.0), 0.00001));
+              ::testing::DoubleNear(std::sqrt(4.0/11.0),  std::numeric_limits<double>::epsilon()));
 }
 
 TEST(Vector, DotProductIsSumOfElementProducts) {
@@ -153,9 +153,9 @@ TEST(Vector, DotProductIsSumOfElementProducts) {
 TEST(Vector, UnitFunctionCreatesNewVectorOverMagnitude) {
   double sq = std::sqrt(14);
   auto unit = iota3i().unit();
-  EXPECT_THAT(unit[0], ::testing::DoubleNear(1/sq, 0.00001));
-  EXPECT_THAT(unit[1], ::testing::DoubleNear(2/sq, 0.00001));
-  EXPECT_THAT(unit[2], ::testing::DoubleNear(3/sq, 0.00001));
+  EXPECT_THAT(unit[0], ::testing::DoubleNear(1/sq,  std::numeric_limits<double>::epsilon()));
+  EXPECT_THAT(unit[1], ::testing::DoubleNear(2/sq,  std::numeric_limits<double>::epsilon()));
+  EXPECT_THAT(unit[2], ::testing::DoubleNear(3/sq,  std::numeric_limits<double>::epsilon()));
 }
 
 TEST(Vector, CanCastEntireVectorThroughConstructor) {