c++/3713: Pointers to functions or member functions are not compile-time constants

c++/3713: Pointers to functions or member functions are not compile-time constants

[philippeb]

>Number:         3713
>Category:       c++
>Synopsis:       Pointers to functions or member functions are not compile-time constants
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jul 17 10:16:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     g++ 2.95.4
>Release:        20010319 (Debian prerelease)
>Organization:
>Environment:
Debian Linux on i386
>Description:
Pointers to functions or member functions are not compile-time constants, meaning that the functions won't be inlined, even if the function is not virtual. It seems also that 'const' modifiers applied to pointers to member are discarded (tested by calling a template function).

The attached program demontrates the problem by confirming that the compiler needs references to those constants:

/tmp/ccQihCjs.o: In function `main':
/home/philippeb/devel/tests/inlineptf.cpp:17: undefined reference to `A::p'
/home/philippeb/devel/tests/inlineptf.cpp:17: undefined reference to `A::p'
>How-To-Repeat:

>Fix:
Don't use a pointer to function if you want your code to be inlined.
>Release-Note:
>Audit-Trail:
>Unformatted:
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Re: c++/3713: Pointers to functions or member functions are not compile-time constants

[lerdsuwa]

Synopsis: Pointers to functions or member functions are not compile-time constants

State-Changed-From-To: closed->open
State-Changed-By: lerdsuwa
State-Changed-When: Mon Sep 17 07:22:53 2001
State-Changed-Why:
    Test case reopened.  After the fix, and compile with
    optimization, function is still not inlined.  Dump of
    assembly in followup shown in PR4277.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view&pr=3713&database=gcc

Re: c++/3713: Pointers to functions or member functions are not compile-time constants

[lerdsuwa]

Synopsis: Pointers to functions or member functions are not compile-time constants

State-Changed-From-To: open->closed
State-Changed-By: lerdsuwa
State-Changed-When: Fri Aug 10 08:37:51 2001
State-Changed-Why:
    Not a bug.  A::p must be defined somewhere outside the class
    A.  The following is the correct version of the code:
    
    #include <iostream>
    using namespace std;
    
    struct A
    {
            void foo()
            {
                    cout << __PRETTY_FUNCTION__ << endl;
            }
    			// This must be defined later
            static void (A::* const p)() = & A::foo;
    };
    void (A::* const A::p)();	// Definition
    
    int main()
    {
            A a;
            (a.*A::p)();
    }

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view&pr=3713&database=gcc