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