libstdc++/9320: Incorrect usage of traits_type::int_type in stdio_filebuf
peturr02@ru.is
peturr02@ru.is
Wed Jan 15 10:26:00 GMT 2003
>Number: 9320
>Category: libstdc++
>Synopsis: Incorrect usage of traits_type::int_type in stdio_filebuf
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: unassigned
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Wed Jan 15 02:26:01 PST 2003
>Closed-Date:
>Last-Modified:
>Originator: peturr02@ru.is
>Release: gcc-3.2.1
>Organization:
>Environment:
Red Hat Linux 8.0
>Description:
The constructors for __gnu_cxx::stdio_filebuf<> take an int_type parameter that is used to specify a buffer size.
However, stdio_filebuf<> has the same template parameters as basic_filebuf<>, so I assume that the same constraits are set on int_type, i.e. int_type is not required to be an integer type (or convertible to one).
In any case this is a bad example for any users wishing to derive their own classes from basic_streambuf<> or basic_filebuf<>.
>How-To-Repeat:
See attachment (should compile, but doesn't).
>Fix:
Use streamsize instead of int_type for the constructors.
>Release-Note:
>Audit-Trail:
>Unformatted:
----gnatsweb-attachment----
Content-Type: text/plain; name="inttypebug.cc"
Content-Disposition: inline; filename="inttypebug.cc"
#include <ext/stdio_filebuf.h>
struct MyChar
{
int val;
};
struct MyInt
{
long val;
};
class MyState
{
};
class MyTraits
{
public:
typedef MyChar char_type;
typedef MyInt int_type;
typedef std::streampos pos_type;
typedef std::streamoff off_type;
typedef MyState state_type;
static void
assign(char_type& __c1, const char_type& __c2);
static bool
eq(const char_type& __c1, const char_type& __c2);
static bool
lt(const char_type& __c1, const char_type& __c2);
static int
compare(const char_type* __s1, const char_type* __s2, size_t __n);
static size_t
length(const char_type* __s);
static const char_type*
find(const char_type* __s, size_t __n, const char_type& __a);
static char_type*
move(char_type* __s1, const char_type* __s2, size_t __n);
static char_type*
copy(char_type* __s1, const char_type* __s2, size_t __n);
static char_type*
assign(char_type* __s, size_t __n, char_type __a);
static char_type
to_char_type(const int_type& __c);
static int_type
to_int_type(const char_type& __c);
static bool
eq_int_type(const int_type& __c1, const int_type& __c2);
static int_type
eof();
static int_type
not_eof(const int_type& __c);
};
template class std::basic_streambuf<MyChar, MyTraits>;
template class std::basic_filebuf<MyChar, MyTraits>;
template class __gnu_cxx::stdio_filebuf<MyChar, MyTraits>;
int main()
{
typedef __gnu_cxx::stdio_filebuf<MyChar, MyTraits> buf_type;
buf_type buf1 (static_cast<FILE*>(0), std::ios_base::in);
buf_type buf2 (0, std::ios_base::in, false, MyInt());
return 0;
}
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