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/* operator>> -- C++-style input of mpf_t.
Copyright 2001, 2003 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 https://www.gnu.org/licenses/. */
#include <cctype>
#include <iostream>
#include <string>
#include <clocale> // for localeconv
#include "gmp.h"
#include "gmp-impl.h"
using namespace std;
// For g++ libstdc++ parsing see num_get<chartype,initer>::_M_extract_float
// in include/bits/locale_facets.tcc.
//
// There are no plans to accept hex or octal floats, not unless the standard
// C++ library does so. Although such formats might be of use, it's
// considered more important to be compatible with what the normal
// operator>> does on "double"s etc.
istream &
operator>> (istream &i, mpf_ptr f)
{
int base;
char c = 0;
string s;
bool ok = false;
// C decimal point, as expected by mpf_set_str
const char *lconv_point = GMP_DECIMAL_POINT;
// C++ decimal point
#if HAVE_STD__LOCALE
const locale& loc = i.getloc();
char point_char = use_facet< numpunct<char> >(loc).decimal_point();
#else
const char *point = lconv_point;
char point_char = *point;
#endif
i.get(c); // start reading
if (i.flags() & ios::skipws) // skip initial whitespace
{
// C++ isspace
#if HAVE_STD__LOCALE
const ctype<char>& ct = use_facet< ctype<char> >(loc);
#define cxx_isspace(c) (ct.is(ctype_base::space,(c)))
#else
#define cxx_isspace(c) isspace(c)
#endif
while (cxx_isspace(c) && i.get(c))
;
}
if (c == '-' || c == '+') // sign
{
if (c == '-')
s = "-";
i.get(c);
}
base = 10;
__gmp_istream_set_digits(s, i, c, ok, base); // read the number
// look for the C++ radix point, but put the C one in for mpf_set_str
if (c == point_char)
{
#if HAVE_STD__LOCALE
i.get(c);
#else // lconv point can be multi-char
for (;;)
{
i.get(c);
point++;
if (*point == '\0')
break;
if (c != *point)
goto fail;
}
#endif
s += lconv_point;
__gmp_istream_set_digits(s, i, c, ok, base); // read the mantissa
}
if (ok && (c == 'e' || c == 'E')) // exponent
{
s += c;
i.get(c);
ok = false; // exponent is mandatory
if (c == '-' || c == '+') // sign
{
s += c;
i.get(c);
}
__gmp_istream_set_digits(s, i, c, ok, base); // read the exponent
}
if (i.good()) // last character read was non-numeric
i.putback(c);
else if (i.eof() && ok) // stopped just before eof
i.clear(ios::eofbit);
if (ok)
ASSERT_NOCARRY (mpf_set_str(f, s.c_str(), base)); // extract the number
else
{
fail:
i.setstate(ios::failbit); // read failed
}
return i;
}
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