[noetic] deprecate h for hpp

[sloretz]

This is another PR created with the goal of shrinking the diff in #32. It deprecates .h files in favor of .hpp in the same way it was done for class_loader. I git mv'd the .h files to .hpp in one commit, added new .h files with the deprecation warning in another, and fixed all the deprecation warnings in this package in the last commit.

Deprecation warnings prior to fixing; proof the header warnings work

In file included from /home/sloretz/ws/filters/src/filters/src/mean.cpp:30:0:
/home/sloretz/ws/filters/src/filters/include/filters/mean.h:40:2: warning: #warning Including header <filters/mean.h> is deprecated, include <filters/mean.hpp> instead. [-Wcpp]
 #warning Including header <filters/mean.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/src/transfer_function.cpp:30:0:
/home/sloretz/ws/filters/src/filters/include/filters/transfer_function.h:40:2: warning: #warning Including header <filters/transfer_function.h> is deprecated, include <filters/transfer_function.hpp> instead. [-Wcpp]
 #warning Including header <filters/transfer_function.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/src/test_params.cpp:31:0:
/home/sloretz/ws/filters/src/filters/include/filters/param_test.h:40:2: warning: #warning Including header <filters/param_test.h> is deprecated, include <filters/param_test.hpp> instead. [-Wcpp]
 #warning Including header <filters/param_test.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/src/median.cpp:31:0:
/home/sloretz/ws/filters/src/filters/include/filters/median.h:40:2: warning: #warning Including header <filters/median.h> is deprecated, include <filters/median.hpp> instead. [-Wcpp]
 #warning Including header <filters/median.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/src/increment.cpp:30:0:
/home/sloretz/ws/filters/src/filters/include/filters/increment.h:40:2: warning: #warning Including header <filters/increment.h> is deprecated, include <filters/increment.hpp> instead. [-Wcpp]
 #warning Including header <filters/increment.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/include/filters/./param_test.hpp:37:0,
                 from /home/sloretz/ws/filters/src/filters/include/filters/param_test.h:44,
                 from /home/sloretz/ws/filters/src/filters/src/test_params.cpp:31:
/home/sloretz/ws/filters/src/filters/include/filters/filter_base.h:40:2: warning: #warning Including header <filters/filter_base.h> is deprecated, include <filters/filter_base.hpp> instead. [-Wcpp]
 #warning Including header <filters/filter_base.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/include/filters/./increment.hpp:37:0,
                 from /home/sloretz/ws/filters/src/filters/include/filters/increment.h:44,
                 from /home/sloretz/ws/filters/src/filters/src/increment.cpp:30:
/home/sloretz/ws/filters/src/filters/include/filters/filter_base.h:40:2: warning: #warning Including header <filters/filter_base.h> is deprecated, include <filters/filter_base.hpp> instead. [-Wcpp]
 #warning Including header <filters/filter_base.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/include/filters/./mean.hpp:39:0,
                 from /home/sloretz/ws/filters/src/filters/include/filters/mean.h:44,
                 from /home/sloretz/ws/filters/src/filters/src/mean.cpp:30:
/home/sloretz/ws/filters/src/filters/include/filters/filter_base.h:40:2: warning: #warning Including header <filters/filter_base.h> is deprecated, include <filters/filter_base.hpp> instead. [-Wcpp]
 #warning Including header <filters/filter_base.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/include/filters/./transfer_function.hpp:41:0,
                 from /home/sloretz/ws/filters/src/filters/include/filters/transfer_function.h:44,
                 from /home/sloretz/ws/filters/src/filters/src/transfer_function.cpp:30:
/home/sloretz/ws/filters/src/filters/include/filters/filter_base.h:40:2: warning: #warning Including header <filters/filter_base.h> is deprecated, include <filters/filter_base.hpp> instead. [-Wcpp]
 #warning Including header <filters/filter_base.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/include/filters/./median.hpp:39:0,
                 from /home/sloretz/ws/filters/src/filters/include/filters/median.h:44,
                 from /home/sloretz/ws/filters/src/filters/src/median.cpp:31:
/home/sloretz/ws/filters/src/filters/include/filters/filter_base.h:40:2: warning: #warning Including header <filters/filter_base.h> is deprecated, include <filters/filter_base.hpp> instead. [-Wcpp]
 #warning Including header <filters/filter_base.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/include/filters/./mean.hpp:42:0,
                 from /home/sloretz/ws/filters/src/filters/include/filters/mean.h:44,
                 from /home/sloretz/ws/filters/src/filters/src/mean.cpp:30:
/home/sloretz/ws/filters/src/filters/include/filters/realtime_circular_buffer.h:40:2: warning: #warning Including header <filters/realtime_circular_buffer.h> is deprecated, include <filters/realtime_circular_buffer.hpp> instead. [-Wcpp]
 #warning Including header <filters/realtime_circular_buffer.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/include/filters/./median.hpp:41:0,
                 from /home/sloretz/ws/filters/src/filters/include/filters/median.h:44,
                 from /home/sloretz/ws/filters/src/filters/src/median.cpp:31:
/home/sloretz/ws/filters/src/filters/include/filters/realtime_circular_buffer.h:40:2: warning: #warning Including header <filters/realtime_circular_buffer.h> is deprecated, include <filters/realtime_circular_buffer.hpp> instead. [-Wcpp]
 #warning Including header <filters/realtime_circular_buffer.h> is deprecated, \
  ^~~~~~~
In file included from /home/sloretz/ws/filters/src/filters/include/filters/./transfer_function.hpp:42:0,
                 from /home/sloretz/ws/filters/src/filters/include/filters/transfer_function.h:44,
                 from /home/sloretz/ws/filters/src/filters/src/transfer_function.cpp:30:
/home/sloretz/ws/filters/src/filters/include/filters/realtime_circular_buffer.h:40:2: warning: #warning Including header <filters/realtime_circular_buffer.h> is deprecated, include <filters/realtime_circular_buffer.hpp> instead. [-Wcpp]
 #warning Including header <filters/realtime_circular_buffer.h> is deprecated, \
  ^~~~~~~

grep to make sure all includes use .hpp and not .h

$ grep . -R -e "include.*filters/.*h"
./src/median.cpp:#include "filters/median.hpp"
./src/test_params.cpp:#include "filters/param_test.hpp"
./src/mean.cpp:#include "filters/mean.hpp"
./src/increment.cpp:#include "filters/increment.hpp"
./src/transfer_function.cpp:#include "filters/transfer_function.hpp"
Binary file ./.git/index matches
./test/test_chain.cpp:#include "filters/filter_chain.hpp"
./test/test_mean.cpp:#include "filters/mean.hpp"
./test/test_params.cpp:#include "filters/param_test.hpp"
./test/test_transfer_function.cpp:#include "filters/transfer_function.hpp"
./test/test_realtime_circular_buffer.cpp:#include "filters/realtime_circular_buffer.hpp"
./test/test_median.cpp:#include "filters/median.hpp"
Binary file ./include/filters/.swp matches
./include/filters/param_test.hpp:#include "filters/filter_base.hpp"
./include/filters/increment.hpp:#include "filters/filter_base.hpp"
Binary file ./include/filters/.param_test.h.swp matches
Binary file ./include/filters/.increment.h.swp matches
Binary file ./include/filters/.mean.h.swp matches
./include/filters/mean.h:#pragma message("include <filters/mean.hpp> instead.")
./include/filters/mean.h:include <filters/mean.hpp> instead.
./include/filters/transfer_function.h:#pragma message("include <filters/transfer_function.hpp> instead.")
./include/filters/transfer_function.h:include <filters/transfer_function.hpp> instead.
./include/filters/filter_chain.hpp:#include "filters/filter_base.hpp"
./include/filters/transfer_function.hpp:#include "filters/filter_base.hpp"
./include/filters/transfer_function.hpp:#include "filters/realtime_circular_buffer.hpp"
./include/filters/median.h:#pragma message("include <filters/median.hpp> instead.")
./include/filters/median.h:include <filters/median.hpp> instead.
./include/filters/filter_base.h:#pragma message("include <filters/filter_base.hpp> instead.")
./include/filters/filter_base.h:include <filters/filter_base.hpp> instead.
./include/filters/filter_chain.h:#pragma message("include <filters/filter_chain.hpp> instead.")
./include/filters/filter_chain.h:include <filters/filter_chain.hpp> instead.
Binary file ./include/filters/.realtime_circular_buffer.h.swp matches
Binary file ./include/filters/.transfer_function.h.swp matches
./include/filters/median.hpp:#include "filters/filter_base.hpp"
./include/filters/median.hpp:#include "filters/realtime_circular_buffer.hpp"
./include/filters/mean.hpp:#include "filters/filter_base.hpp"
./include/filters/mean.hpp:#include "filters/realtime_circular_buffer.hpp"
Binary file ./include/filters/.filter_chain.h.swp matches
./include/filters/increment.h:#pragma message("include <filters/increment.hpp> instead.")
./include/filters/increment.h:include <filters/increment.hpp> instead.
Binary file ./include/filters/.filter_base.h.swp matches
Binary file ./include/filters/.median.h.swp matches
./include/filters/param_test.h:#pragma message("include <filters/param_test.hpp> instead.")
./include/filters/param_test.h:include <filters/param_test.hpp> instead.
./include/filters/realtime_circular_buffer.h:#pragma message("include <filters/realtime_circular_buffer.hpp> instead.")
./include/filters/realtime_circular_buffer.h:include <filters/realtime_circular_buffer.hpp> instead.

[clalancette]

I did a diff of the .h and .hpp before and after this commit, respectively. The only differences between them are the name of the includes. However, I also think the include header guards should be changed as well to match the new .hpp extension. Otherwise this looks good to me.

[clalancette]

The include guard should be:

Suggested change

	#ifndef FILTERS_FILTER_BASE_H_
	#define FILTERS_FILTER_BASE_H_
	#ifndef FILTERS_FILTER_BASE_HPP_
	#define FILTERS_FILTER_BASE_HPP_

The same goes for all of the other header files below.

[sloretz]

Updated include guards in 552f6b3

[tfoote]

Looks good to merge with one small typo unrelated, but we might as well fix it.

[mikaelarguedas]

Could the new headers be back-ported to melodic ? currently it is inconvenient to get a melodic/noetic compatible code that compiles without warnings

[peci1]

I use

#if ROS_VERSION_MINIMUM(1, 15, 0)
#include <filters/filter_chain.hpp>
#else
#include <filters/filter_chain.h>
#endif

to get melodic/noetic compatible code.