ceph/src/boost/libs/format/example/sample_userType.cpp

   1 // ----------------------------------------------------------------------------
   2 // sample_userType.cc :  example usage of format with a user-defined type
   3 // ----------------------------------------------------------------------------
   4
   5 //  Copyright Samuel Krempp 2003. Use, modification, and distribution are
   6 //  subject to the Boost Software License, Version 1.0. (See accompanying
   7 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   8
   9 //  See http://www.boost.org/libs/format for library home page
  10
  11 // ----------------------------------------------------------------------------
  12
  13
  14 #include <iostream>
  15 #include <iomanip>
  16 #include "boost/format.hpp"
  17 #include <boost/cast.hpp>
  18
  19 #if !(BOOST_WORKAROUND(__GNUC__, < 3) && defined(__STL_CONFIG_H) )
  20   // not for broken gcc stdlib
  21 #include <boost/io/ios_state.hpp>
  22
  23 #else
  24 // not as complete, but compatible with gcc-2.95 :
  25
  26 void copyfmt(ios& left, const ios& right) {
  27     left.fill(right.fill());
  28     left.flags(right.flags() );
  29     left.exceptions(right.exceptions());
  30     left.width(right.width());
  31     left.precision(right.precision());
  32 }
  33
  34 namespace boost { namespace io {
  35 class ios_all_saver {
  36     std::basic_ios<char>  ios_;
  37     std::ios & target_r;
  38 public:
  39     ios_all_saver(std::ios& right) : ios_(0), target_r(right) {
  40         copyfmt(ios_, right);
  41     }
  42     ~ios_all_saver() {
  43         copyfmt(target_r, ios_);
  44     }
  45 };
  46
  47 } } // N.S. boost::io
  48
  49
  50 // define showpos and noshowpos :
  51 class ShowPos {
  52 public:
  53     bool showpos_;
  54     ShowPos(bool v) : showpos_(v) {}
  55 };
  56 std::ostream& operator<<(std::ostream& os, const ShowPos& x) {
  57     if(x.showpos_)
  58         os.setf(ios_base:: showpos);
  59     else
  60         os.unsetf(ios_base:: showpos);
  61     return os;
  62 }
  63 ShowPos noshowpos(false);
  64 ShowPos showpos(true);
  65
  66 #endif // -end gcc-2.95 workarounds
  67
  68
  69
  70 //---------------------------------------------------------------------------//
  71 //  *** an exemple of UDT : a Rational class ****
  72 class Rational {
  73 public:
  74   Rational(int n, unsigned int d) : n_(n), d_(d) {}
  75   Rational(int n, int d);    // convert denominator to unsigned
  76   friend std::ostream& operator<<(std::ostream&, const Rational&);
  77 private:
  78   int n_;               // numerator
  79   unsigned int d_;      // denominator
  80 };
  81
  82 Rational::Rational(int n, int d) : n_(n)
  83 {
  84   if(d < 0) { n_ = -n_; d=-d; } // make the denominator always non-negative.
  85     d_ = static_cast<unsigned int>(d);
  86 }
  87
  88 std::ostream& operator<<(std::ostream& os, const Rational& r) {
  89   using namespace std;
  90   streamsize  n, s1, s2, s3;
  91   streamsize w = os.width(0); // width has to be zeroed before saving state.
  92 //  boost::io::ios_all_saver  bia_saver (os);
  93
  94   boost::io::basic_oaltstringstream<char> oss;
  95   oss.copyfmt(os );
  96   oss << r.n_;
  97   s1 = oss.size();
  98   oss << "/" << noshowpos; // a rational number needs only one sign !
  99   s2 = oss.size();
 100   oss << r.d_ ;
 101   s3 = oss.size();
 102
 103   n = w - s3;
 104   if(n <= 0) {
 105       os.write(oss.begin(), oss.size());
 106   }
 107   else if(os.flags() & std::ios_base::internal) {
 108     std::streamsize n1 = w/2, n2 = w - n1,  t;
 109     t = (s3-s1) - n2; // is 2d part '/nnn' bigger than 1/2 w ?
 110     if(t > 0)  {
 111       n1 = w -(s3-s1); // put all paddings on first part.
 112       n2 = 0; // minimal width (s3-s2)
 113     }
 114     else {
 115       n2 -= s2-s1; // adjust for '/',   n2 is still w/2.
 116     }
 117     os << setw(n1) << r.n_ << "/" << noshowpos << setw(n2) << r.d_;
 118   }
 119   else {
 120     if(! (os.flags() & std::ios_base::left)) {
 121         // -> right align. (right bit is set, or no bit is set)
 122         os << string(boost::numeric_cast<std::string::size_type>(n), ' ');
 123     }
 124     os.write(oss.begin(), s3);
 125     if( os.flags() & std::ios_base::left ) {
 126       os << string(boost::numeric_cast<std::string::size_type>(n), ' ');
 127     }
 128   }
 129
 130   return os;
 131 }
 132
 133
 134
 135 int main(){
 136     using namespace std;
 137     using boost::format;
 138     using boost::io::group;
 139     using boost::io::str;
 140     string s;
 141
 142     Rational  r(16, 9);
 143
 144     cout << "bonjour ! " << endl;
 145     // "bonjour !"
 146
 147     cout << r << endl;
 148     // "16/9"
 149
 150     cout << showpos << r << ", " << 5 << endl;
 151     // "+16/9, +5"
 152
 153     cout << format("%02d : [%0+9d] \n") % 1 % r ;
 154     // "01 : [+016 / 0009]"
 155
 156     cout << format("%02d : [%_+9d] \n") % 2 % Rational(9,160);
 157     // "02 : [+9 / 160]"
 158
 159     cout << format("%02d : [%_+9d] \n") % 3 % r;
 160     // "03 : [+16 / 9]"
 161
 162     cout << format("%02d : [%_9d] \n") % 4 % Rational(8,1234);
 163     // "04 : [8 / 1234]"
 164
 165     cout << format("%02d : [%_9d] \n") % 5 % Rational(1234,8);
 166     // "05 : [1234 / 8]"
 167
 168     cout << format("%02d : [%09d] \n") % 6 % Rational(8,1234);
 169     // "06 : [0008 / 1234]"
 170
 171     cout << format("%02d : [%0+9d] \n") % 7 % Rational(1234,8);
 172     // "07 : [+1234 / 008]"
 173
 174     cout << format("%02d : [%0+9d] \n") % 8 % Rational(7,12345);
 175     // "08 : [+07 / 12345]"
 176
 177
 178     cerr << "\n\nEverything went OK, exiting. \n";
 179     return 0;
 180 }