1/*
2Copyright (C) 1993 Free Software Foundation
3
4This file is part of the GNU IO Library.  This library is free
5software; you can redistribute it and/or modify it under the
6terms of the GNU General Public License as published by the
7Free Software Foundation; either version 2, or (at your option)
8any later version.
9
10This library is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this library; see the file COPYING.  If not, write to the Free
17Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
18
19As a special exception, if you link this library with files
20compiled with a GNU compiler to produce an executable, this does not cause
21the resulting executable to be covered by the GNU General Public License.
22This exception does not however invalidate any other reasons why
23the executable file might be covered by the GNU General Public License. */
24
25#include <iostream.h>
26
27static int __xalloc = 0;
28
29int ios::xalloc()
30{
31  return __xalloc++;
32}
33
34static ios::fmtflags __used_fmt_flags
35= ios::skipws | ios::left | ios::right | ios::internal
36| ios::dec | ios::oct | ios::hex | ios::showbase | ios::showpoint
37| ios::uppercase | ios::showpos | ios::scientific | ios::fixed
38#ifndef _IO_NEW_STREAMS
39| ios::dont_close
40#endif
41| ios::unitbuf | ios::stdio;
42
43ios::fmtflags ios::bitalloc()
44{
45  fmtflags bit_to_try = (fmtflags)1;
46  for (; bit_to_try; bit_to_try <<= 1)
47    {
48      if ((__used_fmt_flags & bit_to_try) == 0)
49	{
50	  __used_fmt_flags |= bit_to_try;
51	  return bit_to_try;
52	}
53    }
54  return 0;
55}
56
57// NOTE:  This implementation of ios::iword and ios::pword assumes
58// that these methods are seldom used, so we want to minimize
59// the space and time overhead when NOT using these methods.
60//
61// ANSI specifies two conceptually-infinite arrays, one whose
62// elements are longs, and one whose elements are (void*)s.
63// We implement this as a single array, each of whose element is
64// a (struct ptr_and_long), which has space for both a long and a void*.
65// We also specify that (the i field of) the 0'th element of the array
66// contains the allocated length of the array (not counting that
67// initial element).
68
69struct ptr_and_long {
70  void *p;
71  long i;
72};
73
74static struct ptr_and_long&
75get_array_element(ios& io, int index)
76{
77  if (index < 0)
78    io._throw_failure();
79  register struct ptr_and_long *array = (ptr_and_long*)io._arrays;
80  int old_length = array == NULL ? 0 : array[0].i;
81  if (index >= old_length)
82    {
83      register int i;
84      int new_length = index + 10;
85      register struct ptr_and_long *new_array
86	= new ptr_and_long[1 + new_length];
87      if (array != NULL)
88	{
89	  for (i = 1; i <= old_length; i++)
90	    new_array[i] = array[i];
91	  delete [] array;
92	}
93      for (i = old_length + 1; i <= new_length; i++)
94	{
95	  new_array[i].i = 0;
96	  new_array[i].p = NULL;
97	}
98      new_array[0].i = new_length;
99      new_array[0].p = NULL;
100      io._arrays = (void*)new_array;
101      array = new_array;
102    }
103  return array[index+1];
104}
105
106long& ios::iword(int index)
107{
108  return get_array_element(*this, index).i;
109}
110
111void*& ios::pword(int index)
112{
113  return get_array_element(*this, index).p;
114}
115
116long ios::iword(int index) const
117{
118  if (index < 0)
119    _throw_failure();
120  register struct ptr_and_long *pl_array = (ptr_and_long*)_arrays;
121  int len = pl_array == NULL ? 0 : pl_array[0].i;
122  return index >= len ? 0 : pl_array[index+1].i;
123}
124
125void* ios::pword(int index) const
126{
127  if (index < 0)
128    _throw_failure();
129  register struct ptr_and_long *pl_array = (ptr_and_long*)_arrays;
130  int len = pl_array == NULL ? 0 : pl_array[0].i;
131  return index >= len ? 0 : pl_array[index+1].p;
132}
133