[Bug libstdc++/44952] #include <iostream.h> imply global constructor.

["pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #4 from pinskia at gcc dot gnu dot org  2010-07-15 16:30 -------
(In reply to comment #2)
> Why's this not in libstdc++.so .init?

because this will not work if libstdc++ is a static library.
Take:

#include <iostream>

namespace {
struct g
{
  g(){ std::cout << "t"; }
};
g one;
}

--- CUT ---
The C++ standard says order of initializers between TUs is unspecified (though
the order inside TUs is specified as being the first one will run first).
So with a static version, the above will be included first and that will cause
std::cout to be used without being initialized.

>... and are we required to emit the constructor even if we know var is not
used?
It is hard to do that in Standard C++ really or imposable.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44952