boost::property_tree XML pretty printing

Question

I\'m using boost::property_tree to read and write XML configuration files in my application. But when I write the file the output looks kind of ugly with lots of empty lines

Answer 1

For those trying:

boost::property_tree::xml_writer_settings settings('\t', 1);

Compiling with boost-1.60.0 in VisualStudio 2013 you may get:

vmtknetworktest.cpp(259) : see reference to class template instantiation 'boost::property_tree::xml_parser::xml_writer_settings' being compiled
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(38): error C2039: 'value_type' : is not a member of '`global namespace''
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(38): error C2146: syntax error : missing ';' before identifier 'Ch'
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(38): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(40): error C2061: syntax error : identifier 'Ch'
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(49): error C2146: syntax error : missing ';' before identifier 'indent_char'
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(49): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(50): error C2825: 'Str': must be a class or namespace when followed by '::'
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(50): error C2039: 'size_type' : is not a member of '`global namespace''
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(50): error C2146: syntax error : missing ';' before identifier 'indent_count'
install\include\boost-1_60\boost/property_tree/detail/xml_parser_writer_settings.hpp(50): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
vmtknetworktest.cpp(259): error C2661: 'boost::property_tree::xml_parser::xml_writer_settings::xml_writer_settings' : no overloaded function takes 3 arguments

Then end up here:

https://svn.boost.org/trac/boost/ticket/10272

Solution to found to work is to use std::string in template.

pt::write_xml(file_name, params, std::locale(), pt::xml_writer_make_settings< std::string >(' ', 4));

as described here:

https://stackoverflow.com/a/35043551/7170333