On Thu, 5 Jan 2012, Marc Glisse wrote:
Do you have any suggestion on what libstdc++ can do when faced with C
libraries that will randomly declare gets or not depending on flags? It would
need knowledge of these exact flags so it can provide a replacement exactly
when it isn't declared (or at least remove the using ::gets in that case,
even if that is non-standard). The easiest workaround I can think of is to
implement a failsafe version of using in the front-end, but there might be
better solutions.
Maybe a C++03 version of some fancy template game like this?
#ifndef NOGETS
char* gets(char*){std::cout << "from libc\n";return 0;}
#endif
namespace Help1 {
struct Toobad{};
Toobad gets(...);
}
namespace Help2 {
using namespace Help1;
template<class T> struct A {
static const bool
value=std::is_same<decltype(gets(std::declval<T>())),Help1::Toobad>::value
&& std::is_convertible<T,char*>::value;
};
}
template<class T> typename std::enable_if<Help2::A<T>::value,char*>::type
gets(T x){ std::cout << "from libstdc++, call fgets\n";return 0; }
Certainly not completely legal, but might be close enough?
--
Marc Glisse
