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From: "vagran.ast" <vagran.ast@gmail.com>
To: gcc-help@gcc.gnu.org
Subject: Template argument (pointer to member function) initialization with NULL
Date: Mon, 14 Nov 2011 21:48:00 -0000	[thread overview]
Message-ID: <4EC1789A.2070209@gmail.com> (raw)

Hi,

In the following code:

class A {
public:
     void SomeMethod() { }
};

template <class T, void (T::*SomeMethod)() = 0>
class B {

};

B<A> b1; // error: could not convert template argument '0' to 'void 
(A::*)()'

B<A, 0> b2; // error: could not convert template argument '0' to 'void 
(A::*)()'

void (A::*someMethod)() = 0; // OK

there are two compilation errors. AFAIK per C++ standard 0 is a valid 
value for a pointer to member
function. Variable of such type can be successfully initialized by 0 but 
template arguments can not.
Is it desired behavior or a bug?

gcc version 4.6.1

             reply	other threads:[~2011-11-14 20:23 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-14 21:48 vagran.ast [this message]
2011-11-14 21:51 ` Jonathan Wakely
2011-11-15 13:15   ` vagran.ast
2011-11-15 19:55     ` Jonathan Wakely
2011-11-16 21:11       ` vagran.ast

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