-2002-02-26 Loren Rittle <ljrittle@acm.org>
+2002-02-26 Benjamin Kosnik <bkoz@redhat.com>
+
+ * include/bits/basic_ios.tcc (basic_ios::init): Set _M_fill to zero.
+ Adjust comment.
+ * include/bits/basic_ios.h (basic_ios::_M_fill): Make mutable.
+ (basic_ios::_M_fill_init): New.
+ (basic_ios::fill()): Deal with _M_fill lazily.
+ Adjust comment.
+ * testsuite/27_io/ios_init.cc (test02): Adjust testcase.
+
+2002-02-26 Loren Rittle <ljrittle@acm.org>
* include/Makefile.am (thread_target_headers): Unconditionally
stage and install gthr-posix.h.
// Data members:
protected:
basic_ostream<_CharT, _Traits>* _M_tie;
- char_type _M_fill;
+ mutable char_type _M_fill;
+ mutable bool _M_fill_init;
iostate _M_exception;
basic_streambuf<_CharT, _Traits>* _M_streambuf;
char_type
fill() const
- { return _M_fill; }
+ {
+ if (!_M_fill_init)
+ {
+ _M_fill = this->widen(' ');
+ _M_fill_init = true;
+ }
+ return _M_fill;
+ }
char_type
fill(char_type __ch)
_M_cache_facets(_M_ios_locale);
_M_tie = 0;
- // NB: The 27.4.4.1 Postconditions Table only specifies
- // requirements after basic_ios::init() has been called. As part
- // of this, fill() must return widen(' '), which needs an imbued
- // ctype facet of char_type to return without throwing an
- // exception. Unfortunately, ctype<char_type> is not necessarily a
- // required facet, so streams with char_type != [char, wchar_t]
- // will not have it by default. However, because fill()'s
- // signature is const, this data member cannot be lazily
- // initialized. Thus, thoughts of using a non-const helper
- // function in ostream inserters is really besides the point.
- _M_fill = this->widen(' ');
+ // NB: The 27.4.4.1 Postconditions Table specifies requirements
+ // after basic_ios::init() has been called. As part of this,
+ // fill() must return widen(' ') any time after init() has been
+ // called, which needs an imbued ctype facet of char_type to
+ // return without throwing an exception. Unfortunately,
+ // ctype<char_type> is not necessarily a required facet, so
+ // streams with char_type != [char, wchar_t] will not have it by
+ // default. Because of this, the correct value for _M_fill is
+ // constructed on the first call of fill(). That way,
+ // unformatted input and output with non-required basic_ios
+ // instantiations is possible even without imbuing the expected
+ // ctype<char_type> facet.
+ _M_fill = 0;
+ _M_fill_init = false;
_M_exception = goodbit;
_M_streambuf = __sb;
}
// Non-required instantiations don't have the required facets inbued,
-// by default, into the locale object. As such, basic_ios::init is
-// required to return a bad_cast for the first use of fill() call.
+// by default, into the locale object.
// See 27.4.4.1
-
class gnu_ios: public std::basic_ios<char> { };
void test02()
bool test = true;
// 01: Doesn't call basic_ios::init, which uses ctype<char_type>..
+ // This should be unambiguously correct.
try
{
gnu_ios gios;
test = false;
}
- // 02: Calls basic_ios::init, which uses ctype<char_type>..
+ // 02: Calls basic_ios::init, which may call ctype<char_type>...
try
{
std::basic_string<unsigned short> str;
std::basic_ostringstream<unsigned short> oss(str);
- // Shouldn't get this far.
- test = false;
-
// Try each member functions for unformatted io.
// put
oss.put(324);
}
catch(const std::bad_cast& obj)
{
- // This is correct.
+ // Should be able to do the above without calling fill() and
+ // forcing a call to widen...
+ test = false;
}
catch(...)
{