Re: [boost] Complier bug taking the address of an instantiated member function template ?

Subject: Re: [boost] Complier bug taking the address of an instantiated member function template ?
From: Edward Diener (eldiener_at_[hidden])
Date: 2011-03-15 16:31:22

On 3/15/2011 4:10 PM, Doug Gregor wrote:
> On Tue, Mar 15, 2011 at 1:01 PM, Edward Diener<eldiener_at_[hidden]>  wrote:
>> Apologies as this is off-topic, as it refers to C++ and not Boost, but I
>> have run into this working with my TTI library in the sandbox and hopefully
>> some Boost developer has run into this and can tell me whether all compilers
>> are broken or I am doing something completely wrong in my use of C++ syntax:
>>
>> The code:
>>
>> "struct AType
>>   {
>>   double SomeFunc(int,long *,double&) { double ret(0); return ret; }
>>   template<class X,class Y,class Z,short AA>  double SomeFuncTemplate(X,Y *,Z
>> &) { double ret(AA); return ret; }
>>   };
>>
>> template
>>   <
>>   class T
>>   >
>> struct TTest
>>   {
>>   typedef char Bad;
>>   struct Good { char x[2]; };
>>   template<T>  struct helper;
>>   static Good check(helper<&AType::template
>> SomeFuncTemplate<int,long,double,50>  >  *);
>>   static Bad check(...);
>>   static const bool value=sizeof(check(0))==sizeof(Good);
>>   };
>>
>> template
>>   <
>>   class T,
>>   class C
>>   >
>> struct TTest1
>>   {
>>   typedef char Bad;
>>   struct Good { char x[2]; };
>>   template<T>  struct helper;
>>   template<class U>  static Good check(helper<&U::SomeFunc>  *);
>>   template<class U>  static Bad check(...);
>>   static const bool value=sizeof(check<C>(0))==sizeof(Good);
>>   };
>>
>> template
>>   <
>>   class T,
>>   class C
>>   >
>> struct TTest2
>>   {
>>   typedef char Bad;
>>   struct Good { char x[2]; };
>>   template<T>  struct helper;
>>   template<class U>  static Good check(helper<&U::template
>> SomeFuncTemplate<int,long,double,50>  >  *);
>>   template<class U>  static Bad check(...);
>>   static const bool value=sizeof(check<C>(0))==sizeof(Good);
>>   };
>>
>> int main()
>>   {
>>
>>   static_assert(TTest
>>                   <
>>                   double (AType::*)(int,long *,double&)
>>                   >::value,
>>                 "failure in TTest"
>>                );
>>
>>   static_assert(TTest1
>>                   <
>>                   double (AType::*)(int,long *,double&),
>>                   AType
>>                   >::value,
>>                 "failure in TTest1"
>>                );
>>
>>   static_assert(TTest2
>>                   <
>>                   double (AType::*)(int,long *,double&),
>>                   AType
>>                   >::value,
>>                 "failure in TTest2"
>>                );
>>
>>   return 0;
>>
>>   }"
>>
>> Both gcc 4.5.2 ( with -std=c++0x ) and msvc 10.0 put out the static assert
>> "failure in TTest2". I do not see why this is happening. I have no tried
>> clang, but if I could figure out how to use it in Windows I would.
>>
>> Anyone ?
>
> The code looks well-formed to me; Clang accepts it.

Thanks, I will post this on gcc and VC++ NGs/Forums and see what people 
say there. Strange that both should work incorrectly.