Use of deprecated std::binary_function, std::unary_function, and std::interface

[bneradt]

I updated our CI Fedora image to fedora:36. fedora:36 has gcc-12 as its default toolset. When I did a test build with this, the build failed with the following deprecation warning:

ccache c++ -DHAVE_CONFIG_H -I. -I../../include  -Dlinux -DDEBUG -D_DEBUG -D_LARGEFILE64_SOURCE=1 -D_COMPILE64BIT_SOURCE=1 -D_REENTRANT -D__STDC_LIMIT_MACROS=1 -D__STDC_FORMAT_MACROS=1 -I/home/jenkins/workspace/Github_Builds/fedora/src/iocore/eventsystem -I/home/jenkins/workspace/Github_Builds/fedora/src/iocore/utils -I/home/jenkins/workspace/Github_Builds/fedora/src/mgmt -I/home/jenkins/workspace/Github_Builds/fedora/src/mgmt/api/include -I/home/jenkins/workspace/Github_Builds/fedora/src/mgmt/utils -I/home/jenkins/workspace/Github_Builds/fedora/src/include -I/home/jenkins/workspace/Github_Builds/fedora/src/lib  -D_GNU_SOURCE -DOPENSSL_NO_SSL_INTERN -std=c++17 -ggdb3 -pipe -Wall -Wextra -Wno-ignored-qualifiers -Wno-unused-parameter -Wno-format-truncation -Wno-cast-function-type -Wno-stringop-overflow -Werror -Wno-invalid-offsetof -Wno-noexcept-type -mcx16  -MT RecLocal.o -MD -MP -MF $depbase.Tpo -c -o RecLocal.o RecLocal.cc &&\
mv -f $depbase.Tpo $depbase.Po
In file included from ../../include/tscore/MemArena.h:32,
                 from ../records/I_RecHttp.h:32,
                 from RecHttp.cc:25:
../../include/tscore/IntrusivePtr.h:333:29: error: 'template<class _Arg1, class _Arg2, class _Result> struct std::binary_function' is deprecated [-Werror=deprecated-declarations]
  333 |   class Order : public std::binary_function<IntrusivePtr<T>, IntrusivePtr<T>, bool>
      |                             ^~~~~~~~~~~~~~~
In file included from /usr/include/c++/12/functional:49,
                 from ../records/I_RecCore.h:26,
                 from RecHttp.cc:24:
/usr/include/c++/12/bits/stl_function.h:131:12: note: declared here
  131 |     struct binary_function
      |            ^~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
make[2]: *** [Makefile:1040: RecHttp.o] Error 1
make[2]: *** Waiting for unfinished jobs....
In file included from ../../include/tscore/MemArena.h:32,
                 from ../records/I_RecHttp.h:32,
                 from ../../mgmt/LocalManager.h:29,
                 from RecLocal.cc:32:
../../include/tscore/IntrusivePtr.h:333:29: error: 'template<class _Arg1, class _Arg2, class _Result> struct std::binary_function' is deprecated [-Werror=deprecated-declarations]
  333 |   class Order : public std::binary_function<IntrusivePtr<T>, IntrusivePtr<T>, bool>
      |                             ^~~~~~~~~~~~~~~
In file included from /usr/include/c++/12/string:48,
                 from ../../include/tscore/ink_memory.h:30,
                 from ../../include/tscore/defalloc.h:25,
                 from ../../include/tscore/List.h:60,
                 from ../../mgmt/ConfigManager.h:27,
                 from RecLocal.cc:25:
/usr/include/c++/12/bits/stl_function.h:131:12: note: declared here
  131 |     struct binary_function
      |            ^~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
make[2]: *** [Makefile:1040: RecLocal.o] Error 1
make[2]: Leaving directory '/home/jenkins/workspace/Github_Builds/fedora/src/lib/records'
make[1]: *** [Makefile:603: all-recursive] Error 1
make[1]: Leaving directory '/home/jenkins/workspace/Github_Builds/fedora/src/lib'
make: *** [Makefile:874: all-recursive] Error 1

[bneradt]

This can be reproduced via the CI's fedora:36 Docker image like so:

docker pull controller.trafficserver.org/ats/fedora:36
docker run -it controller.trafficserver.org/ats/fedora:36 /bin/bash
cd /var/tmp
git clone https://github.com/apache/trafficserver.git
cd trafficserver
autoreconf -fiv
./configure --with-openssl=/opt/openssl-quic --enable-experimental-plugins --enable-example-plugins --prefix=/tmp/ats/ --enable-werror --enable-debug --enable-wccp --enable-luajit --enable-ccache
make -j4 V=1 Q=

[bneradt]

std::binary_function is used in the following three places:

• include/tscore/IntrusivePtr.h
• lib/swoc/include/swoc/DiscreteRange.h
• src/wccp/WccpMeta.h

It looks like in general the interface can just be dropped unless the specific typedefs it provides are needed, which seems rare:
https://stackoverflow.com/a/33115140/629530

I therefore intend to create a PR that simply removes the binary_function inheritance.

@SolidWallOfCode : Note the usage of deprecated interface std::binary_function in libswoc's DiscreteRange.h above.

[bneradt]

This same problem also occurs with std::unary_operator and std::iterator in addition to std::binary_operator. These are all interfaces that provide typedefs but have since been deprecated because it is considered better to simply define these definitions in the class that needs them. #8684 replaces the use of these interfaces and explicitly provides the associated type definitions.