$ g++ -std=c++0x T1.cpp -lcryptopp -o T1

In file included from /usr/include/boost/property_tree/json_parser.hpp:17,
                 from T1.cpp:6:
/usr/include/boost/property_tree/json_parser/detail/write.hpp: In instantiation of ‘void boost::property_tree::json_parser::write_json_helper(std::basic_ostream<typename Ptree::key_type::value_type>&, const Ptree&, int, bool) [with Ptree = boost::property_tree::basic_ptree<std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> > > >; typename Ptree::key_type::value_type = char; typename Ptree::key_type::value_type = char]’:
/usr/include/boost/property_tree/json_parser/detail/write.hpp:160:26:   required from ‘void boost::property_tree::json_parser::write_json_internal(std::basic_ostream<typename Ptree::key_type::value_type>&, const Ptree&, const string&, bool) [with Ptree = boost::property_tree::basic_ptree<std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> > > >; typename Ptree::key_type::value_type = char; typename Ptree::key_type::value_type = char; std::string = std::__cxx11::basic_string<char>]’
/usr/include/boost/property_tree/json_parser.hpp:99:28:   required from ‘void boost::property_tree::json_parser::write_json(std::basic_ostream<typename Ptree::key_type::value_type>&, const Ptree&, bool) [with Ptree = boost::property_tree::basic_ptree<std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> > > >; typename Ptree::key_type::value_type = char; typename Ptree::key_type::value_type = char]’

################# SEE HERE #####################
T1.cpp:33:46:   required from here
/usr/include/boost/property_tree/json_parser/detail/write.hpp:84:48: error: cannot convert ‘Str’ {aka ‘std::__cxx11::basic_string<char>’} to ‘const key_type&’ {aka ‘const std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >&’}
   84 |         else if (indent > 0 && pt.count(Str()) == pt.size())
In file included from /usr/include/boost/property_tree/ptree.hpp:516,
                 from T1.cpp:5:
/usr/include/boost/property_tree/detail/ptree_implementation.hpp:518:53: note:   initializing argument 1 of ‘boost::property_tree::basic_ptree<Key, Data, KeyCompare>::size_type boost::property_tree::basic_ptree<Key, Data, KeyCompare>::count(const key_type&) const [with Key = std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >; Data = std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >; KeyCompare = std::less<std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> > >; boost::property_tree::basic_ptree<Key, Data, KeyCompare>::size_type = long unsigned int; boost::property_tree::basic_ptree<Key, Data, KeyCompare>::key_type = std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >]’
  518 |         basic_ptree<K, D, C>::count(const key_type &key) const
      |                                     ~~~~~~~~~~~~~~~~^~~
In file included from /usr/include/boost/property_tree/json_parser.hpp:17,
                 from T1.cpp:6:

################# AND HERE #####################
/usr/include/boost/property_tree/json_parser/detail/write.hpp:111:52: error: no matching function for call to ‘create_escapes(const std::__cxx11::basic_string<char, std::char_traits<char>, CryptoPP::AllocatorWithCleanup<char> >&)’
  111 |                 stream << Ch('"') << create_escapes(it->first) << Ch('"') << Ch(':');
      |                                      ~~~~~~~~~~~~~~^~~~~~~~~~~
/usr/include/boost/property_tree/json_parser/detail/write.hpp:25:27: note: candidate: ‘template<class Ch> std::__cxx11::basic_string<_CharT> boost::property_tree::json_parser::create_escapes(const std::__cxx11::basic_string<_CharT>&)’
   25 |     std::basic_string<Ch> create_escapes(const std::basic_string<Ch> &s)
      |                           ^~~~~~~~~~~~~~
/usr/include/boost/property_tree/json_parser/detail/write.hpp:25:27: note:   template argument deduction/substitution failed:
/usr/include/boost/property_tree/json_parser/detail/write.hpp:111:52: note:   mismatched types ‘std::allocator<_CharT>’ and ‘CryptoPP::AllocatorWithCleanup<char>’
  111 |                 stream << Ch('"') << create_escapes(it->first) << Ch('"') << Ch(':');
      |                                      ~~~~~~~~~~~~~~^~~~~~~~~~~