[Bug c++/44267] SFINAE does not handle down static_cast over virtual inheritance

[cjoldfield at gmail dot com]

--- Comment #2 from cjoldfield at gmail dot com  2010-05-25 17:09 ---
Intel 11.1 accepts it, but it doesn't even try to instantiate one f(...). 
To see what I mean, try replacing main with:

#include iostream
int main()
{
   std::cout  sizeof(fD*, int(0))  std::endl;
   std::cout  sizeof(fD*, B*(0))  std::endl;
   std::cout  sizeof(fVD*, B*(0)) std::endl;
}

Also for intel, if one forces it to try to instantiate one f(...) by
removing two f(...), it will complain that there is no matching call to
f...(0) for all three calls (it should match the second).  In this situation,
gcc only complains about the first and the last, which is the expected
behavior.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44267

[Bug c++/44267] New: SFINAE does not handle down static_cast over virtual inheritance

[cjoldfield at gmail dot com]

g++ fails to overlook template instantiation errors involving down static_casts
over virtual inheritance boundaries. Example:

struct B {};
struct D : B {};
struct VD : virtual B {};

template class T T create();

typedef char one[1];
typedef char two[2];

template class D, class B
one f(char (*)[sizeof(static_castD(createB()))]);

template class D, class B
two f(...);

int main()
{
   fD*, int(0);
   fD*, B*(0);
   fVD*, B*(0);
   return 0;
}

gives error: cannot convert from base ‘B’ to derived type ‘VD’ via virtual base
‘B’

Expected behavior is for template instantiation to fail for the first template
f function and selection of the second template f function.  

Same issue for gcc 4.3.4.  

May be related to report 41468.


-- 
   Summary: SFINAE does not handle down static_cast over virtual
inheritance
   Product: gcc
   Version: 4.4.3
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: cjoldfield at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44267

[Bug c++/44239] New: Spurious partial explicit specialization when taking the address of a template function.

[cjoldfield at gmail dot com]

Problem:

template class T
const T max(const T x, const T y){
   return x  y ? x : y;
}

template class T, class C
const T max(const T x, const T y, C comp){
   return comp(x, y) ? y : x;

}

template class R, class A0, class A1
struct functor{
   template class F
   functor(F f) : f(f) {}
   R (*f)(A0, A1);
};

int main(void){
   functorconst int, const int, const int func(maxint); 
   return 0;
}

results in error: no matching function for call to ‘functorconst int, const
int, const int::functor(unresolved overloaded function type)’  Only
candidate constructor is the default copy constructor.

After removing the two parameter max template, compiles clean.  The code is
boiled down from a problem using std::max with boost::function.


-- 
   Summary: Spurious partial explicit specialization when taking the
address of a template function.
   Product: gcc
   Version: 4.3.4
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: cjoldfield at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44239

[Bug c++/44243] New: Spurious partial explicit specialization when taking the address of a template function.

[cjoldfield at gmail dot com]

Problem:

template class T
const T max(const T x, const T y){
   return x  y ? x : y;
}

template class T, class C
const T max(const T x, const T y, C comp){
   return comp(x, y) ? y : x;

}

template class R, class A0, class A1
struct functor{
   template class F
   functor(F f) : f(f) {}
   R (*f)(A0, A1);
};

int main(void){
   functorconst int, const int, const int func(maxint); 
   return 0;
}

results in error: no matching function for call to ‘functorconst int, const
int, const int::functor(unresolved overloaded function type)’  Only
candidate constructor is the default copy constructor.

After removing the two parameter max template, compiles clean.  The code is
boiled down from a problem using std::max with boost::function.


-- 
   Summary: Spurious partial explicit specialization when taking the
address of a template function.
   Product: gcc
   Version: 4.3.4
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: cjoldfield at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44243

[Bug c++/44243] Spurious partial explicit specialization when taking the address of a template function.

[cjoldfield at gmail dot com]

--- Comment #1 from cjoldfield at gmail dot com  2010-05-22 17:33 ---


*** This bug has been marked as a duplicate of 44239 ***


-- 

cjoldfield at gmail dot com changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution||DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44243

[Bug c++/44239] Spurious partial explicit specialization when taking the address of a template function.

[cjoldfield at gmail dot com]

--- Comment #2 from cjoldfield at gmail dot com  2010-05-22 17:33 ---
*** Bug 44243 has been marked as a duplicate of this bug. ***


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44239