cleaning, replace with c++17 idioms

Makefile

@@ -71,6 +71,7 @@ help:
 	@echo " - install: copies into /usr/local/include (requires 'sudo')"
 	@echo " - clean: erase all build files"
 	@echo " - test-bg: builds and runs the Boost::geometry polygon binding test file"
+	@echo " - test-rtp: builds and runs the 3 tests files fo Run Time Polymorphism"
 	@echo " - showcase: builds an runs the \"showcase\" page gif images"
 	@echo "* Available options (OPTION=Y|N)"
 	@echo "  - USE_OPENCV : link with Opencv, relevant for 'test' targets"
@@ -258,7 +259,7 @@ BUILD/homog2d_test_rtp_%: misc/test_files/homog2d_test_rtp_%.cpp homog2d.hpp bui
 
 #=======================================================================
 # speed test
-speed_test: speed_test_b
+speed-test: speed_test_b
 	@time BUILD/ellipse_speed_test_SYCN
 	@time BUILD/ellipse_speed_test_SY
 	@time BUILD/ellipse_speed_test_SN

docs/homog2d_speed.md

@@ -6,17 +6,17 @@ As detailed [in manual](homog2d_manual.md#build_options), the
 `HOMOG2D_OPTIMIZE_SPEED` build option will favor speed over memory footprint.
 At present, this only has an impact on the `Ellipse_` class behavior.
 
-With current commit (2022-11-10), and using the
-`$ make speed_test`
-command that builds and runs the program [`ellipse_speed_test.cpp`](../misc/ellipse_speed_test.cpp) with different options, the results are as follow:
+With release 2.12 and using the
+`speed-test` make target that
+builds and runs the program [`ellipse_speed_test.cpp`](../misc/ellipse_speed_test.cpp) with different options, the results are as follow:
 
 | Build Option | Ellipse footprint (bytes) |  Duration (s)  |
 |--------------|---------------------------|----------------|
-| (none)                                       |  88 | 4.75 |
-| HOMOG2D_OPTIMIZE_SPEED                       | 160 | 3.32 |
-| HOMOG2D_OPTIMIZE_SPEED <br> HOMOG2D_NOCHECKS | 160 | 2.26 |
+| (none)                                       |  80 | 4.75 |
+| HOMOG2D_OPTIMIZE_SPEED                       | 152 | 3.32 |
+| HOMOG2D_OPTIMIZE_SPEED <br> HOMOG2D_NOCHECKS | 152 | 2.26 |
 
-- Test machine: Dell 5510 core I7, Ubuntu 20.04
+- Test machine: Dell 5510 core I7, Ubuntu 22.04
 - Number of runs: 1E7 (default value)
 
 Those values are just to have an idea and are variable with several runs.