>From description of moneypunct<> facet(22.2.6.3, p3):
The format of the numeric monetary value is a decimal number:
value ::= units [ decimal-point [ digits ]] | decimal-point digits
if frac_digits() returns a positive value, or
value ::= units
otherwise.
But the implementation of money_get<>::do_get() reads from input stream decimal
point and digits after it and write them to the result(units or digits), even
when frac_digits() return nonpositive value.
In similar situation with grouping, when grouping string indicates that
grouping shouldn't not be applied, implementation stops read when it encounters
thousands separator.
Example:
#include <locale>
#include <sstream>
#include <iostream>
using namespace std;
class my_moneypunct : public moneypunct<char>
{
protected:
//this should disable fraction part of monetary value
int do_frac_digits()const {return 0;}
};
int main()
{
locale loc(locale(), new my_moneypunct());
stringstream ss("123.456");
ss.imbue(loc);
string digits;
ios_base::iostate err;
use_facet<money_get<char> >(loc).get(ss, 0, false, ss, err, digits);
string rest(istreambuf_iterator<char>(ss), istreambuf_iterator<char>());
cout << "digits is \"" << digits << "\"\n";
cout << "rest of stream is \"" << rest << "\"\n";
return 0;
}
[EMAIL PROTECTED] money_get_frac_digits]$ g++ ./test.cpp && ./a.out
digits is "123456"
rest of stream is ""
[EMAIL PROTECTED] money_get_frac_digits]$ g++ --version
g++ (GCC) 4.3.0 20080428 (Red Hat 4.3.0-8)
Copyright (C) 2008 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
--
Summary: money_get<> read decimal point when frac_digits() <= 0
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tsyvarev at ispras dot ru
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38399
