isfuns.cc
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上传日期:2022-08-06
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文件大小:2k
- /* Auxiliary functions for C++-style input of GMP types.
- Copyright 2001 Free Software Foundation, Inc.
- This file is part of the GNU MP Library.
- The GNU MP Library is free software; you can redistribute it and/or modify
- it under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 3 of the License, or (at your
- option) any later version.
- The GNU MP Library is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
- License for more details.
- You should have received a copy of the GNU Lesser General Public License
- along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
- #include <cctype>
- #include <iostream>
- #include <string>
- #include "gmp.h"
- #include "gmp-impl.h"
- using namespace std;
- int
- __gmp_istream_set_base (istream &i, char &c, bool &zero, bool &showbase)
- {
- int base;
- zero = showbase = false;
- switch (i.flags() & ios::basefield)
- {
- case ios::dec:
- base = 10;
- break;
- case ios::hex:
- base = 16;
- break;
- case ios::oct:
- base = 8;
- break;
- default:
- showbase = true; // look for initial "0" or "0x" or "0X"
- if (c == '0')
- {
- if (! i.get(c))
- c = 0; // reset or we might loop indefinitely
- if (c == 'x' || c == 'X')
- {
- base = 16;
- i.get(c);
- }
- else
- {
- base = 8;
- zero = true; // if no other digit is read, the "0" counts
- }
- }
- else
- base = 10;
- break;
- }
- return base;
- }
- void
- __gmp_istream_set_digits (string &s, istream &i, char &c, bool &ok, int base)
- {
- switch (base)
- {
- case 10:
- while (isdigit(c))
- {
- ok = true; // at least a valid digit was read
- s += c;
- if (! i.get(c))
- break;
- }
- break;
- case 8:
- while (isdigit(c) && c != '8' && c != '9')
- {
- ok = true; // at least a valid digit was read
- s += c;
- if (! i.get(c))
- break;
- }
- break;
- case 16:
- while (isxdigit(c))
- {
- ok = true; // at least a valid digit was read
- s += c;
- if (! i.get(c))
- break;
- }
- break;
- }
- }