diff --git a/src/json/geojson_grammar_x3.cpp b/src/json/geojson_grammar_x3.cpp
index 5d3964fe1..cf08bab75 100644
--- a/src/json/geojson_grammar_x3.cpp
+++ b/src/json/geojson_grammar_x3.cpp
@@ -35,4 +35,4 @@ BOOST_SPIRIT_INSTANTIATE_UNUSED(geojson_grammar_type, iterator_type, extract_bou
 }}}
 
 
-template bool mapnik::json::grammar::parse_rule<char const*, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::__1::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, boost::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, boost::bimaps::set_of<int, std::__1::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::__1::reference_wrapper<mapnik::json::extract_positions<char const*, std::__1::vector<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> >, std::__1::allocator<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::__1::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > >, boost::spirit::x3::unused_type const>(boost::spirit::x3::rule<mapnik::json::grammar::geojson_tag, mapnik::json::geojson_value, false>, char const*&, char const* const&, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::__1::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, boost::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, boost::bimaps::set_of<int, std::__1::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::__1::reference_wrapper<mapnik::json::extract_positions<char const*, std::__1::vector<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> >, std::__1::allocator<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::__1::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > > const&, boost::spirit::x3::unused_type const&);
+template bool mapnik::json::grammar::parse_rule<char const*, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::hash<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, boost::bimaps::set_of<int, std::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::reference_wrapper<mapnik::json::extract_positions<char const*, std::vector<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> >, std::allocator<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > >, boost::spirit::x3::unused_type const>(boost::spirit::x3::rule<mapnik::json::grammar::geojson_tag, mapnik::json::geojson_value, false>, char const*&, char const* const&, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::hash<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, boost::bimaps::set_of<int, std::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::reference_wrapper<mapnik::json::extract_positions<char const*, std::vector<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> >, std::allocator<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > > const&, boost::spirit::x3::unused_type const&);
diff --git a/src/json/positions_grammar_x3.cpp b/src/json/positions_grammar_x3.cpp
index 9d5417e46..18112cfde 100644
--- a/src/json/positions_grammar_x3.cpp
+++ b/src/json/positions_grammar_x3.cpp
@@ -37,4 +37,4 @@ BOOST_SPIRIT_INSTANTIATE_UNUSED(positions_grammar_type, iterator_type, extract_b
 }}}
 
 
-template bool mapnik::json::grammar::parse_rule<char const*, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::__1::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, boost::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, boost::bimaps::set_of<int, std::__1::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::__1::reference_wrapper<mapnik::json::extract_positions<char const*, std::__1::vector<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> >, std::__1::allocator<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::__1::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > >, mapbox::util::variant<mapnik::geometry::point<double>, std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > >, std::__1::vector<std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > >, std::__1::allocator<std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > > > > > >(boost::spirit::x3::rule<mapnik::json::grammar::positions_tag, mapbox::util::variant<mapnik::geometry::point<double>, std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > >, std::__1::vector<std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > >, std::__1::allocator<std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > > > > >, false>, char const*&, char const* const&, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::__1::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, boost::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, boost::bimaps::set_of<int, std::__1::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::__1::reference_wrapper<mapnik::json::extract_positions<char const*, std::__1::vector<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> >, std::__1::allocator<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::__1::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > > const&, mapbox::util::variant<mapnik::geometry::point<double>, std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > >, std::__1::vector<std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > >, std::__1::allocator<std::__1::vector<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > >, std::__1::allocator<std::__1::vector<mapnik::geometry::point<double>, std::__1::allocator<mapnik::geometry::point<double> > > > > > > >&);
+template bool mapnik::json::grammar::parse_rule<char const*, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::hash<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, boost::bimaps::set_of<int, std::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::reference_wrapper<mapnik::json::extract_positions<char const*, std::vector<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> >, std::allocator<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > >, mapbox::util::variant<mapnik::geometry::point<double>, std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > >, std::vector<std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > >, std::allocator<std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > > > > > >(boost::spirit::x3::rule<mapnik::json::grammar::positions_tag, mapbox::util::variant<mapnik::geometry::point<double>, std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > >, std::vector<std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > >, std::allocator<std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > > > > >, false>, char const*&, char const* const&, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::hash<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, boost::bimaps::set_of<int, std::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::reference_wrapper<mapnik::json::extract_positions<char const*, std::vector<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> >, std::allocator<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > > const&, mapbox::util::variant<mapnik::geometry::point<double>, std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > >, std::vector<std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > >, std::allocator<std::vector<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > >, std::allocator<std::vector<mapnik::geometry::point<double>, std::allocator<mapnik::geometry::point<double> > > > > > > >&);
diff --git a/src/json/unicode_string_grammar_x3.cpp b/src/json/unicode_string_grammar_x3.cpp
index 4626ecada..41f18c289 100644
--- a/src/json/unicode_string_grammar_x3.cpp
+++ b/src/json/unicode_string_grammar_x3.cpp
@@ -40,7 +40,7 @@ BOOST_SPIRIT_INSTANTIATE_UNUSED(unicode_string_grammar_type, iterator_type, extr
 }}}
 
 
-template bool mapnik::json::grammar::parse_rule<char const*, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::__1::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, boost::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, boost::bimaps::set_of<int, std::__1::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::__1::reference_wrapper<mapnik::json::extract_positions<char const*, std::__1::vector<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> >, std::__1::allocator<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::__1::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > >, boost::spirit::x3::unused_type const>(boost::spirit::x3::rule<mapnik::json::grammar::unicode_string_tag, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, false>, char const*&, char const* const&, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::__1::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, boost::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, boost::bimaps::set_of<int, std::__1::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::__1::reference_wrapper<mapnik::json::extract_positions<char const*, std::__1::vector<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> >, std::__1::allocator<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::__1::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > > const&, boost::spirit::x3::unused_type const&);
+template bool mapnik::json::grammar::parse_rule<char const*, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::hash<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, boost::bimaps::set_of<int, std::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::reference_wrapper<mapnik::json::extract_positions<char const*, std::vector<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> >, std::allocator<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > >, boost::spirit::x3::unused_type const>(boost::spirit::x3::rule<mapnik::json::grammar::unicode_string_tag, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, false>, char const*&, char const* const&, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::hash<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, boost::bimaps::set_of<int, std::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::reference_wrapper<mapnik::json::extract_positions<char const*, std::vector<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> >, std::allocator<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > > const&, boost::spirit::x3::unused_type const&);
 
 
-template bool mapnik::json::grammar::parse_rule<char const*, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::__1::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, boost::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, boost::bimaps::set_of<int, std::__1::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::__1::reference_wrapper<mapnik::json::extract_positions<char const*, std::__1::vector<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> >, std::__1::allocator<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::__1::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >(boost::spirit::x3::rule<mapnik::json::grammar::unicode_string_tag, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, false>, char const*&, char const* const&, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::__1::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, boost::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, boost::bimaps::set_of<int, std::__1::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::__1::reference_wrapper<mapnik::json::extract_positions<char const*, std::__1::vector<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> >, std::__1::allocator<std::__1::pair<mapnik::box2d<float>, std::__1::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::__1::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&);
+template bool mapnik::json::grammar::parse_rule<char const*, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::hash<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, boost::bimaps::set_of<int, std::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::reference_wrapper<mapnik::json::extract_positions<char const*, std::vector<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> >, std::allocator<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >(boost::spirit::x3::rule<mapnik::json::grammar::unicode_string_tag, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, false>, char const*&, char const* const&, boost::spirit::x3::context<mapnik::json::grammar::keys_tag, std::reference_wrapper<boost::bimaps::bimap<boost::bimaps::unordered_set_of<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::hash<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, boost::bimaps::set_of<int, std::less<int> >, mpl_::na, mpl_::na, mpl_::na> > const, boost::spirit::x3::context<mapnik::json::grammar::feature_callback_tag, std::reference_wrapper<mapnik::json::extract_positions<char const*, std::vector<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> >, std::allocator<std::pair<mapnik::box2d<float>, std::pair<unsigned long, unsigned long> > > > > > const, boost::spirit::x3::context<mapnik::json::grammar::bracket_tag, std::reference_wrapper<unsigned long> const, boost::spirit::x3::context<boost::spirit::x3::skipper_tag, boost::spirit::x3::char_class<boost::spirit::char_encoding::standard, boost::spirit::x3::space_tag> const, boost::spirit::x3::unused_type> > > > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> >&);