format_test3.cpp

C++的一个好库。。。现在很流行

// ------------------------------------------------------------------------------
// format_test3.cpp :  complicated format strings  and / or advanced uses
// ------------------------------------------------------------------------------

//  Copyright Samuel Krempp 2003. Use, modification, and distribution are
//  subject to the Boost Software License, Version 1.0. (See accompanying
//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

// see http://www.boost.org/libs/format for library home page

// ------------------------------------------------------------------------------

#define BOOST_FORMAT_STATIC_STREAM
#include "boost/format.hpp"

#include <iostream> 
#include <iomanip>

#define BOOST_INCLUDE_MAIN 
#include <boost/test/test_tools.hpp>

struct Rational {
  int n,d;
  Rational (int an, int ad) : n(an), d(ad) {}
};

std::ostream& operator<<( std::ostream& os, const Rational& r) {
  os << r.n << "/" << r.d;
  return os;
}

int test_main(int, char* [])
{
    using namespace std;
    using boost::format;
    using boost::io::group;
    using boost::str;

    string s, s2;
    // special paddings 
    s = str( format("[%=6s] [%+6s] [%+6s] [% 6s] [%+6s]\n") 
                      % 123
                      % group(internal, setfill('W'), 234)
                      % group(internal, setfill('X'), -345)
                      % group(setfill('Y'), 456)
                      % group(setfill('Z'), -10 ) );

    if(s != "[  123 ] [+WW234] [-XX345] [YY 456] [ZZZ-10]\n" ) {
      cerr << s ;
      BOOST_ERROR("formatting error. (with special paddings)");
    }

    s = str( format("[% 6.8s] [% 8.6s] [% 7.7s]\n") 
                      % group(internal, setfill('x'), Rational(12345,54321))
                      % group(internal, setfill('x'), Rational(123,45))
                      % group(internal, setfill('x'), Rational(123,321))
             );
    if(s != (s2="[ 12345/5] [ xx123/4] [ 123/32]\n" )) {
        cerr << s << s2;
      BOOST_ERROR("formatting error. (with special paddings)");
    }

    s = str( format("[% 6.8s] [% 6.8s] [% 6.8s] [% 6.8s] [%6.8s]\n") 
                      % 1234567897
                      % group(setfill('x'), 12)
                      % group(internal, setfill('x'), 12)
                      % group(internal, setfill('x'), 1234567890)
                      % group(internal, setfill('x'), 123456) 
             );
    if(s != (s2="[ 1234567] [xxx 12] [ xxx12] [ 1234567] [123456]\n") ) {
        cerr << s << s2;
      BOOST_ERROR("formatting error. (with special paddings)");
    }

    s = str( format("[% 8.6s] [% 6.4s] [% 6.4s] [% 8.6s] [% 8.6s]\n")
                      % 1234567897
                      % group(setfill('x'), 12)
                      % group(internal, setfill('x'), 12)
                      % group(internal, setfill('x'), 1234567890)
                      % group(internal, setfill('x'), 12345) 
             );
    if(s != (s2="[   12345] [xxx 12] [ xxx12] [ xx12345] [ xx12345]\n") ) {
        cerr << s << s2;
      BOOST_ERROR("formatting error. (with special paddings)");
    }

    // nesting formats :
    s = str( format("%2$014x [%1%] %|2$05|\n") % (format("%05s / %s") % -18 % 7)
             %group(showbase, -100)
             );
    if( s != "0x0000ffffff9c [-0018 / 7] -0100\n" ){
      cerr << s ;
      BOOST_ERROR("nesting did not work");
    }
   
    return 0;
}