The C++ Standard, in section 22.2.6.1.1, says that if money_get::do_get
recognizes a valid sequence then it does not modify the ios_base::iostate
variable passed to it. That variable should be set to eofbit only if do_get
has not recognized a valid sequence and no more characters are available. This
was reported within IBM.
The testcase below gives the following output with GCC 3.3:
Contents of digits = "11"
Contents of retval = " 22"
mystate is goodbit as expected
and the following with later versions, including current mainline:
Contents of digits = "11"
Contents of retval = " 22"
mystate is eofbit, should not have changed
The testcase:
----------------------------------------------------------
#include <locale>
#include <string>
#include <sstream>
#include <cstring>
#include <cstdlib>
// Declare our own version of money_get to get access to do_get.
struct MyMoneyGet : public std::money_get<char, char *>
{
char *
my_do_get (char *pa, char *pz, bool intl,
std::ios_base &myios, std::ios_base::iostate &mystate,
std::string &digits)
{
return do_get (pa, pz, intl, myios, mystate, digits);
}
};
int
main ()
{
std::string digits;
MyMoneyGet mg;
std::ios_base::iostate mystate;
std::stringstream myios;
std::locale mylocale (std::locale::classic (), new std::moneypunct<char>);
myios.imbue (mylocale);
char s1[] = "11 22";
char s2[] = "11"; // use this to get the length we want
char *retval;
size_t len2 = strlen (s2);
// Parse the string "11" from the larger string "11 12"; we do that
// to be able to look at the return value in retval.
mystate = std::ios_base::goodbit;
retval = mg.my_do_get (s1, s1 + len2, false, myios, mystate, digits);
printf ("Contents of digits = \"%s\"\n", digits.c_str ());
printf ("Contents of retval = \"%s\"\n", retval);
if (mystate == std::ios_base::goodbit)
printf ("mystate is goodbit as expected\n");
else
{
if (mystate == std::ios_base::eofbit)
printf ("mystate is eofbit, should not have changed\n");
else
printf ("mystate is %d, should not have changed\n", mystate);
abort ();
}
}
-------------------------------------------------------------------
The behavior changed with:
http://gcc.gnu.org/viewcvs?view=rev&rev=73011
r73011 | paolo | 2003-10-28 17:09:03 +0000 (Tue, 28 Oct 2003)
--
Summary: money_get:do_get incorrectly sets eofbit for valid input
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: janis at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34031
