Mapnik fails to build with Boost 1.83

[SMillerDev]

Trying to compile mapnik with the latest boost gives a long list of:

  In file included from src/json/mapnik_json_geometry_grammar.cpp:23:
  In file included from include/mapnik/json/geometry_grammar_impl.hpp:26:
  In file included from include/mapnik/json/geometry_grammar.hpp:29:
  include/mapnik/json/generic_json.hpp:97:16: error: no member named 'utf8_output_iterator' in namespace 'boost'
          boost::utf8_output_iterator<insert_iter> utf8_iter(out_iter);
          ~~~~~~~^
  include/mapnik/json/generic_json.hpp:97:37: error: unexpected type name 'insert_iter': expected expression
          boost::utf8_output_iterator<insert_iter> utf8_iter(out_iter);
                                      ^
  include/mapnik/json/generic_json.hpp:97:50: error: use of undeclared identifier 'utf8_iter'
          boost::utf8_output_iterator<insert_iter> utf8_iter(out_iter);
                                                   ^
  include/mapnik/json/generic_json.hpp:98:10: error: use of undeclared identifier 'utf8_iter'; did you mean 'out_iter'?
          *utf8_iter++ = code_point;
           ^~~~~~~~~
           out_iter
  include/mapnik/json/generic_json.hpp:96:21: note: 'out_iter' declared here
          insert_iter out_iter(utf8);
                      ^
  In file included from src/json/generic_json.cpp:23:
  include/mapnik/json/generic_json.hpp:97:16: error: no member named 'utf8_output_iterator' in namespace 'boost'
          boost::utf8_output_iterator<insert_iter> utf8_iter(out_iter);
          ~~~~~~~^
  include/mapnik/json/generic_json.hpp:97:37: error: unexpected type name 'insert_iter': expected expression
          boost::utf8_output_iterator<insert_iter> utf8_iter(out_iter);
                                      ^
  include/mapnik/json/generic_json.hpp:97:50: error: use of undeclared identifier 'utf8_iter'
          boost::utf8_output_iterator<insert_iter> utf8_iter(out_iter);
                                                   ^
  include/mapnik/json/generic_json.hpp:98:10: error: use of undeclared identifier 'utf8_iter'; did you mean 'out_iter'?
          *utf8_iter++ = code_point;
           ^~~~~~~~~
           out_iter
  include/mapnik/json/generic_json.hpp:96:21: note: 'out_iter' declared here
          insert_iter out_iter(utf8);
                      ^

[artemp]

@SMillerDev - unicode_iterators are still there but boost_1_83 re-arranged include directives e.g

grep -rn 'utf8_output_iterator' ../boost_1_83_0/boost
../boost_1_83_0/boost/regex/v5/icu.hpp:1199:inline utf8_output_iterator<OutputIterator> make_utf32_out(OutputIterator o, std::integral_constant<int, 1> const*)
../boost_1_83_0/boost/regex/v5/icu.hpp:1250:inline BaseIterator extract_output_base(const utf8_output_iterator<BaseIterator>& b)
../boost_1_83_0/boost/regex/v5/unicode_iterator.hpp:50:class utf8_output_iterator;
../boost_1_83_0/boost/regex/v5/unicode_iterator.hpp:790:class utf8_output_iterator

...

I can't replicate on macOS 13, please provide more details about you build environment.

As a solution try adding #include <boost/regex/icu.hpp> in generic_json.hpp and report back if this fixes compile error.

[SMillerDev]

Oh, probably good to note for this issue that I'm building the latest release of Mapnik.

[hummeltech]

The pull request #4413 should resolve this issue.