EnumIterator inherits from std::iterator base class which is deprecated in c++17

[scpeters]

Environment

• OS Version: macOS 12.6.5 (Monterey) with macOS 13.1 SDK
• Source or binary build? source build of gz-common5 as of 6f5ee94 (other versions too)

excerpt of brew config:

Clang: 14.0.0 build 1400
macOS: 12.6.5-x86_64
CLT: 14.2.0.0.1.1668646533
Xcode: N/A

Description

• Expected behavior: package should compile without warnings
• Actual behavior: deprecation warning from EnumIface.hh when compiling EnumIface_TEST.cc since EnumIterator inherits from std::iterator and the std::iterator base class is deprecated as of c++17

src/EnumIface_TEST.cc:20:
/include/gz/common/EnumIface.hh:145:12: warning: 'iterator<std::bidirectional_iterator_tag, MyType>' is deprecated [-Wdeprecated-declarations]
    : std::iterator<std::bidirectional_iterator_tag, Enum>
           ^
src/EnumIface_TEST.cc:61:32: note: in instantiation of template class 'gz::common::EnumIterator<MyType>' requested here
  common::EnumIterator<MyType> end = MY_TYPE_END;
                               ^
/Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/usr/include/c++/v1/__iterator/iterator.h:27:29: note: 'iterator<std::bidirectional_iterator_tag, MyType>' has been explicitly marked deprecated here
struct _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 iterator
                            ^
/Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/usr/include/c++/v1/__config:1066:39: note: expanded from macro '_LIBCPP_DEPRECATED_IN_CXX17'
#  define _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_DEPRECATED
                                      ^
/Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/usr/include/c++/v1/__config:1043:48: note: expanded from macro '_LIBCPP_DEPRECATED'
#    define _LIBCPP_DEPRECATED __attribute__ ((deprecated))
                                               ^

Steps to reproduce

1. Build from source on macOS Monterey

or

1. Run https://build.osrfoundation.org/view/ign-garden/job/ignition_common-ci-gz-common5-homebrew-amd64 on one of the macOS-monterey nodes

Output

https://build.osrfoundation.org/view/ign-garden/job/ignition_common-ci-gz-common5-homebrew-amd64/37/clang/

[scpeters]

@mjcarroll is there a way to fix this on released versions without breaking API? If not, I think we should suppress the warning and fix it on main

[azeey]

I've added the harmonic label to make sure we include this in Harmonic.

[mjcarroll]

I think we should suppress the warning and fix it on main

We concluded this is the right answer after talking about it at the meeting yesterday.

[scpeters]

@mjcarroll did you have any ideas for how to fix this on main? It's not urgent for Harmonic

[scpeters]

fixed in #529