Считать из файла три предложения и вывести их в обратном порядке - C++

#include <cstddef>
#include <ios>
#include <istream>
#include <ostream>
#include <fstream>
#include <string>
#include <algorithm>
#include <iterator>
#include <vector>
 
::std::string
get_token( ::std::istream & in, ::std::string delim )
{
  typedef ::std::char_traits< char > traits;
  ::std::string ret;
  for( traits::int_type cur( in.get( ) ); ( cur != traits::eof( ) ) && in.good( ); cur = in.get( ) )
  {
    ret.push_back( static_cast< char >( cur ) );
    if( delim.find( static_cast< char >( cur ) ) != ::std::string::npos )
      break;
  }
  return( ret );
}
 
void
reorder( ::std::istream & in, ::std::ostream & out, ::std::size_t limit )
{
  ::std::vector< ::std::string > head;
  for( ; limit != 0; --limit )
    head.push_back( ::get_token( in, ".!?" ) );
 
  ::std::copy( head.rbegin( ), head.rend( ), ::std::ostream_iterator< ::std::string >( out ) );
  out << in.rdbuf( );
}
 
int
main( int argc, char * * argv )
{
  ::std::string in_filename( "input.txt" );
  ::std::string out_filename( "output.txt" );
 
  if( argc > 1 )
    in_filename = argv[ 1 ];
  if( argc > 2 )
    in_filename = argv[ 2 ];
 
  ::std::ifstream input( in_filename.c_str( ), ::std::ios::binary );
  ::std::ofstream output( out_filename.c_str( ), ::std::ios::binary );
  ::reorder( input, output, 3 );
}