[boost] [result_of] BOOST_RESULT_OF_USE_DECLTYPE in a C++03 mode with libc++

Subject: [boost] [result_of] BOOST_RESULT_OF_USE_DECLTYPE in a C++03 mode with libc++
From: Michel Morin (mimomorin_at_[hidden])
Date: 2012-10-08 09:08:45

This is just a small note related to boost::result_of.

When BOOST_RESULT_OF_USE_DECLTYPE is defined,
boost::result_of tries to use decltype-based implementation
(regardless of the compiler's decltype support).

Surprisingly, in a C++03 mode, libc++ defines `decltype`
using `__typeof__`:

  Bug 12488 (WONTFIX):
  decltype can be used in C++03 with no errors, no warnings
  http://llvm.org/bugs/show_bug.cgi?id=12488

So, when used with libc++, boost::result_of can be used with
BOOST_RESULT_OF_USE_DECLTYPE even in a C++03 mode.

Regards,
Michel