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From: "gccearlyadopter@trash-mail.com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/51818] New: [C++0x] Name mangling error using lambda expressions in GCC47
Date: Wed, 11 Jan 2012 01:46:00 -0000	[thread overview]
Message-ID: <bug-51818-4@http.gcc.gnu.org/bugzilla/> (raw)

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51818

             Bug #: 51818
           Summary: [C++0x] Name mangling error using lambda expressions
                    in GCC47
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: gccearlyadopter@trash-mail.com


The following program fails to compile:

#include <iostream>
#include <functional>
using std::cout;
using std::endl;

typedef std::function<void()> void_fun;

struct foo 
{
    void_fun bar = [=]() {
        cout << "foo::bar" << endl;
    };  
    void_fun baz = [=]() {
        cout << "foo::baz" << endl;
    };  
};

int main()
{
    foo f;
    f.bar();
    f.baz();
}


GCC 47 says: ... FATAL:Symbol
__ZSt4moveIRNUlvE_EEONSt16remove_referenceIT_E4typeEOS3_ already defined


Furthermore, it's not possible to call bar() from baz:

minimal_mangling_example.cpp: In lambda function:
minimal_mangling_example.cpp:12:5: error: invalid use of non-static data member
'foo::bar'
minimal_mangling_example.cpp:15:9: error: from this location

Unless the this pointer is passed and used explicitly:

    void_fun baz = [this]() {
        this->baz();
    }; 


That's wrong, too. The standard says in 5.1.2.7 ... "transforming id-
expressions referring to non-static class members into class member access
expressions using (*this) ...". Thus, baz should be able to call bar without
using this:


    void_fun baz = [=]() {
        bar();
    }; 



Best regards.


             reply	other threads:[~2012-01-11  1:46 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-11  1:46 gccearlyadopter@trash-mail.com [this message]
2012-01-11 20:27 ` [Bug c++/51818] " jason at gcc dot gnu.org
2012-01-11 20:40 ` jason at gcc dot gnu.org

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