Re: Invalid C++ or bug in GCC 4.8

From:
Sergey Strukov <sshimnick@this.is.invalid>
Newsgroups:
comp.lang.c++.moderated
Date:
Thu, 27 Jun 2013 05:33:19 -0700 (PDT)
Message-ID:
<5af0e213-ebaa-4635-a199-9b4192179107@googlegroups.com>
??????????????, 27 ???????? 2013 ??., 3:50:01 UTC+4 ????????????????????????
marcel...@googlemail.com ??????????????:

Below is a completely stripped down version of the code. Is this illegal
C++ code, or is this a bug in GCC 4.8?

template <typename Signature, typename TypeId> class ObjectFactory;

template<typename Base , typename TypeId>
class ObjectFactory<Base (), TypeId> { };

struct Abstract { virtual ~Abstract() = 0; };

struct Concrete : Abstract { };

typedef ObjectFactory< Abstract(), int> MyFactory;
</code>

When compiling with GCC 4.8 I get the following error:

Eabstract-class-type.cc:10:33: error: ???type name??? declared as
function returning an abstract class type

 typedef ObjectFactory< Abstract(), int> MyFactory;


You cannot create an object of an abstract class type, so there cannot
be a function with such return type. The compiler error message is
completely reasonable here.

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