Boost C++ Libraries: Ticket #4489: References to function object types

owner changed

Christopher Schmidt — Thu, 29 Jul 2010 17:02:49 GMT

owner changed from No-Maintainer to Douglas Gregor

Christopher Schmidt — Fri, 30 Jul 2010 12:35:46 GMT

"The current implementation of boost::result_of permits Fn in boost::result_of<Fn(Args...)>"...

oh, there is a mistake in there. Of course I meant that the current implementation of boost::result_of does not permit Fn in boost::result_of<Fn(Args...)>"...

description changed

viboes — Sun, 03 Jun 2012 20:41:25 GMT

description modified (diff)

owner changed

Michel Morin — Mon, 04 Jun 2012 10:39:46 GMT

owner changed from Douglas Gregor to Daniel Walker

Michel Morin — Mon, 04 Jun 2012 10:43:09 GMT

Boost's decltype-based result_of already accepts references to function objects. Users can explicitly enable decltype-based result_of by defining BOOST_RESULT_OF_USE_DECLTYPE. Or, in the trunk code, it is automatically enabled when a compiler supports N3276 decltype (e.g. clang-3.1).

For example, on clang-3.1 with the following functor:

struct F
{
    short operator()(int) &  { return 0; }
    float operator()(int) && { return 0; }
};

boost::result_of<F& (int)>::type evaluates to short.
boost::result_of<F&&(int)>::type evaluates to float.

Is this enough for you? Or, do you want this feature in tr1-style result_of?

milestone changed

anonymous — Sat, 01 Sep 2012 21:02:48 GMT

milestone Boost 1.44.0 → To Be Determined

We could update the old TR1 protocol to handle references to function objects, but that would take some refactoring. It could be done at the same time as refactoring for #6731... But updating TR1 result_of is lower priority.

Daniel Walker

component changed

Michel Morin — Tue, 25 Sep 2012 14:02:54 GMT

component utility → result_of