Resolve "Emplace API inconsistent with ProcessorTrackerFeature/Landmark functions"

Closes #191 (closed)

test/gtest_track_matrix.cpp

@@ -25,13 +25,15 @@ class TrackMatrixTest : public testing::Test
         virtual void SetUp()
         {
             // unlinked captures
+            // Some warnings will be thrown "linking with nullptr" for emplacing without providing frame pointer
             C0 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 0.0);
-            C1 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 0.0);
-            C2 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 0.0);
-            C3 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 0.0);
-            C4 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 0.0);
+            C1 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 1.0);
+            C2 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 2.0);
+            C3 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 3.0);
+            C4 = CaptureBase::emplace<CaptureBase>(nullptr, "BASE", 4.0);
 
             // unlinked features
+            // Some warnings will be thrown "linking with nullptr" for emplacing without providing capture pointer
             f0 = FeatureBase::emplace<FeatureBase>(nullptr, "BASE", m, m_cov);
             f1 = FeatureBase::emplace<FeatureBase>(nullptr, "BASE", m, m_cov);
             f2 = FeatureBase::emplace<FeatureBase>(nullptr, "BASE", m, m_cov);