diff options
Diffstat (limited to 'vendor/gmp-6.3.0/cxx/ismpf.cc')
-rw-r--r-- | vendor/gmp-6.3.0/cxx/ismpf.cc | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/vendor/gmp-6.3.0/cxx/ismpf.cc b/vendor/gmp-6.3.0/cxx/ismpf.cc new file mode 100644 index 0000000..9ff25eb --- /dev/null +++ b/vendor/gmp-6.3.0/cxx/ismpf.cc @@ -0,0 +1,144 @@ +/* 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 either: + + * 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. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +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 General Public License +for more details. + +You should have received copies of the GNU General Public License and 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-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; +} |