ubitset.cc

   1 // This file is part of the ustl library, an STL implementation.
   2 //
   3 // Copyright (C) 2005 by Mike Sharov <msharov@users.sourceforge.net>
   4 // This file is free software, distributed under the MIT License.
   5 //
   6 // ubitset.cc
   7 //
   8
   9 #include "ubitset.h"
  10
  11 namespace ustl {
  12
  13 /// Copies bits from \p v of size \p n into \p buf as MSB "1011001..." LSB
  14 /// If \p buf is too small, MSB bits will be truncated.
  15 void convert_to_bitstring (const bitset_value_type* v, size_t n, string& buf)
  16 {
  17     string::iterator stri = buf.end();
  18     for (size_t i = 0; i < n && stri > buf.begin(); ++ i)
  19         for (bitset_value_type b = 1; b && stri > buf.begin(); b <<= 1)
  20             *--stri = (v[i] & b) ? '1' : '0';
  21 }
  22
  23 /// Copies bits from \p buf as MSB "1011001..." LSB into \p v of size \p n.
  24 void convert_from_bitstring (const string& buf, bitset_value_type* v, size_t n)
  25 {
  26     string::const_iterator stri = buf.end();
  27     for (size_t i = 0; i < n; ++ i) {
  28         for (bitset_value_type b = 1; b; b <<= 1) {
  29             if (stri == buf.begin() || *--stri == '0')
  30                 v[i] &= ~b;
  31             else
  32                 v[i] |= b;
  33         }
  34     }
  35 }
  36
  37 } // namespace ustl
  38