[Bug c++/39050] New: [c++0x] rvalue reference & copy construction issue

[s dot gesemann at gmail dot com]

Consider:

   struct S {
   private:
 S(const S&); // no copy-c'tor
   };

   S && ref();

   void f(S);

   void g() {
 f(ref());
   }

This compiles using

   g++ -c -std=c++0x test.cpp

where in fact the compiler should complain about the copy-c'tor not being
public.


-- 
   Summary: [c++0x] rvalue reference & copy construction issue
   Product: gcc
   Version: 4.3.2
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: s dot gesemann at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39050

[Bug c++/40944] New: [C++0x] rejects well-formed code: SFINAE, decltype, function call

[s dot gesemann at gmail dot com]

I think the following code is well-formed and should compile with the
-std=c++0x switch:

   #include 

   template
   struct make { static T&& it(); };

   template
   struct exists { typedef R type; };

   template< typename Func, typename T >
   void bar(T const& x,
 typename exists<
   int,
   decltype( make::it()(make::it()) ) // SFINAE!
 >::type = 0
   ) {
 std::cout << "bar-1\n";
   }

   template< typename Func >
   void bar(...) {
 std::cout << "bar-2\n";
   }

   int main() {
 bar(42);
   }

I expect it to compile and print "bar-2". Instead, the compiler rejects the
code with the error

   invalid initialization of reference >int&< with an expression of
   type >const int<.

Cheers!
SG


-- 
   Summary: [C++0x] rejects well-formed code: SFINAE, decltype,
function call
   Product: gcc
   Version: 4.4.1
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
    AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: s dot gesemann at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40944

[Bug c++/39050] [c++0x] rvalue reference & copy construction issue

[s dot gesemann at gmail dot com]

--- Comment #1 from s dot gesemann at gmail dot com  2009-02-02 15:18 
---
This is probably just another manifestation of the same bug (#36744)

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36744


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39050

[Bug c++/40944] [C++0x] rejects well-formed code: SFINAE, decltype, function call

[s dot gesemann at gmail dot com]

--- Comment #2 from s dot gesemann at gmail dot com  2009-08-16 12:48 
---
This is probably a related (SFINAE<->decltype) problem:


template
struct meta {
   static T&& m();   // make
   static void s(T); // sink
};

// operator()(T&,int) available ?
template::m()(23) )>
int foo(T x) {
   x(23);
   return 1;
}

int foo(...) {
   return 0;
}

int main() {
   return foo(42);
}


As far as I can tell it should compile with -std=c++0x and return 0. Instead,
the compiler rejects the code.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40944

[Bug c++/40944] [C++0x] rejects well-formed code: SFINAE, decltype, function call

[s dot gesemann at gmail dot com]

--- Comment #3 from s dot gesemann at gmail dot com  2009-08-16 13:00 
---
sorry, please disregard my previous comment. I accidentally used GCC 4.3.3
instead of GCC 4.4.1


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40944