This is the mail archive of the gcc-bugs@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[Bug c++/51818] New: [C++0x] Name mangling error using lambda expressions in GCC47


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.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]