In file included from main.cpp:121:0:
format_visitor.h:1:1: error: stray '\357' in program
 include <iostream>
 ^
format_visitor.h:1:2: error: stray '\273' in program
 include <iostream>
  ^
format_visitor.h:1:3: error: stray '\277' in program
 include <iostream>
   ^
format_visitor.h:1:4: error: 'include' does not name a type
 include <iostream>
    ^~~~~~~
In file included from /usr/include/c++/7/sstream:826:0,
                 from format_visitor.h:7,
                 from main.cpp:121:
/usr/include/c++/7/bits/sstream.tcc:46:15: error: template definition of non-template 'typename std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::int_type std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::pbackfail'
     pbackfail(int_type __c)
               ^~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:46:15: error: 'int_type' was not declared in this scope
/usr/include/c++/7/bits/sstream.tcc:46:15: note: suggested alternative: '_Bit_type'
     pbackfail(int_type __c)
               ^~~~~~~~
               _Bit_type
/usr/include/c++/7/bits/sstream.tcc:80:14: error: template definition of non-template 'typename std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::int_type std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::overflow'
     overflow(int_type __c)
              ^~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:80:14: error: 'int_type' was not declared in this scope
/usr/include/c++/7/bits/sstream.tcc:80:14: note: suggested alternative: '_Bit_type'
     overflow(int_type __c)
              ^~~~~~~~
              _Bit_type
/usr/include/c++/7/bits/sstream.tcc:150:15: error: invalid use of incomplete type 'class std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>'
     underflow()
               ^
In file included from /usr/include/c++/7/ios:38:0,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from main.cpp:1:
/usr/include/c++/7/iosfwd:96:11: note: declaration of 'class std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>'
     class basic_stringbuf;
           ^~~~~~~~~~~~~~~
In file included from /usr/include/c++/7/sstream:826:0,
                 from format_visitor.h:7,
                 from main.cpp:121:
/usr/include/c++/7/bits/sstream.tcc:168:13: error: template definition of non-template 'typename std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::seekoff'
     seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
             ^~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:168:13: error: 'off_type' was not declared in this scope
/usr/include/c++/7/bits/sstream.tcc:168:13: note: suggested alternative: 'off_t'
     seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
             ^~~~~~~~
             off_t
/usr/include/c++/7/bits/sstream.tcc:168:47: error: expected primary-expression before '__way'
     seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
                                               ^~~~~
/usr/include/c++/7/bits/sstream.tcc:168:73: error: expected primary-expression before '__mode'
     seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
                                                                         ^~~~~~
/usr/include/c++/7/bits/sstream.tcc:216:13: error: template definition of non-template 'typename std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::seekpos'
     seekpos(pos_type __sp, ios_base::openmode __mode)
             ^~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:216:13: error: 'pos_type' was not declared in this scope
/usr/include/c++/7/bits/sstream.tcc:216:13: note: suggested alternative: 'isctype'
     seekpos(pos_type __sp, ios_base::openmode __mode)
             ^~~~~~~~
             isctype
/usr/include/c++/7/bits/sstream.tcc:216:47: error: expected primary-expression before '__mode'
     seekpos(pos_type __sp, ios_base::openmode __mode)
                                               ^~~~~~
/usr/include/c++/7/bits/sstream.tcc:246:13: error: variable or field '_M_sync' declared void
     _M_sync(char_type* __base, __size_type __i, __size_type __o)
             ^~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:246:13: error: 'char_type' was not declared in this scope
/usr/include/c++/7/bits/sstream.tcc:246:13: note: suggested alternative: '_Bit_type'
     _M_sync(char_type* __base, __size_type __i, __size_type __o)
             ^~~~~~~~~
             _Bit_type
/usr/include/c++/7/bits/sstream.tcc:246:24: error: '__base' was not declared in this scope
     _M_sync(char_type* __base, __size_type __i, __size_type __o)
                        ^~~~~~
/usr/include/c++/7/bits/sstream.tcc:246:24: note: suggested alternative: '__bos0'
     _M_sync(char_type* __base, __size_type __i, __size_type __o)
                        ^~~~~~
                        __bos0
/usr/include/c++/7/bits/sstream.tcc:246:32: error: '__size_type' was not declared in this scope
     _M_sync(char_type* __base, __size_type __i, __size_type __o)
                                ^~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:246:32: note: suggested alternative: '__true_type'
     _M_sync(char_type* __base, __size_type __i, __size_type __o)
                                ^~~~~~~~~~~
                                __true_type
/usr/include/c++/7/bits/sstream.tcc:246:49: error: '__size_type' was not declared in this scope
     _M_sync(char_type* __base, __size_type __i, __size_type __o)
                                                 ^~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:246:49: note: suggested alternative: '__true_type'
     _M_sync(char_type* __base, __size_type __i, __size_type __o)
                                                 ^~~~~~~~~~~
                                                 __true_type
/usr/include/c++/7/bits/sstream.tcc:277:14: error: variable or field '_M_pbump' declared void
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
              ^~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:277:14: error: 'char_type' was not declared in this scope
/usr/include/c++/7/bits/sstream.tcc:277:14: note: suggested alternative: '_Bit_type'
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
              ^~~~~~~~~
              _Bit_type
/usr/include/c++/7/bits/sstream.tcc:277:25: error: '__pbeg' was not declared in this scope
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
                         ^~~~~~
/usr/include/c++/7/bits/sstream.tcc:277:25: note: suggested alternative: '_S_beg'
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
                         ^~~~~~
                         _S_beg
/usr/include/c++/7/bits/sstream.tcc:277:33: error: 'char_type' was not declared in this scope
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
                                 ^~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:277:33: note: suggested alternative: '_Bit_type'
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
                                 ^~~~~~~~~
                                 _Bit_type
/usr/include/c++/7/bits/sstream.tcc:277:44: error: '__pend' was not declared in this scope
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
                                            ^~~~~~
/usr/include/c++/7/bits/sstream.tcc:277:44: note: suggested alternative: '__pad'
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
                                            ^~~~~~
                                            __pad
/usr/include/c++/7/bits/sstream.tcc:277:52: error: 'off_type' was not declared in this scope
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
                                                    ^~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:277:52: note: suggested alternative: 'off_t'
     _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
                                                    ^~~~~~~~
                                                    off_t
/usr/include/c++/7/bits/sstream.tcc:291:25: error: explicit instantiation of 'class std::__cxx11::basic_stringbuf<char>' before definition of template
   extern template class basic_stringbuf<char>;
                         ^~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:292:25: error: explicit instantiation of 'class std::__cxx11::basic_istringstream<char>' before definition of template
   extern template class basic_istringstream<char>;
                         ^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:293:25: error: explicit instantiation of 'class std::__cxx11::basic_ostringstream<char>' before definition of template
   extern template class basic_ostringstream<char>;
                         ^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:294:25: error: explicit instantiation of 'class std::__cxx11::basic_stringstream<char>' before definition of template
   extern template class basic_stringstream<char>;
                         ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:297:25: error: explicit instantiation of 'class std::__cxx11::basic_stringbuf<wchar_t>' before definition of template
   extern template class basic_stringbuf<wchar_t>;
                         ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:298:25: error: explicit instantiation of 'class std::__cxx11::basic_istringstream<wchar_t>' before definition of template
   extern template class basic_istringstream<wchar_t>;
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:299:25: error: explicit instantiation of 'class std::__cxx11::basic_ostringstream<wchar_t>' before definition of template
   extern template class basic_ostringstream<wchar_t>;
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/7/bits/sstream.tcc:300:25: error: explicit instantiation of 'class std::__cxx11::basic_stringstream<wchar_t>' before definition of template
   extern template class basic_stringstream<wchar_t>;
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from main.cpp:121:0:
format_visitor.h: In member function 'virtual void FormatVisitor::Visit(const ClassDeclarationNode*)':
format_visitor.h:15:28: error: aggregate 'std::ostringstream line' has incomplete type and cannot be defined
         std::ostringstream line;
                            ^~~~
format_visitor.h: In member function 'virtual void FormatVisitor::Visit(const MethodDeclarationNode*)':
format_visitor.h:37:28: error: aggregate 'std::ostringstream line' has incomplete type and cannot be defined
         std::ostringstream line;
                            ^~~~
format_visitor.h: In member function 'std::__cxx11::string FormatVisitor::getCurrentIdent() const':
format_visitor.h:64:28: error: aggregate 'std::ostringstream res' has incomplete type and cannot be defined
         std::ostringstream res;
                            ^~~