[Bug c++/67952] [C++14] Compilation error with boost::signals2 and generic lambda: cannot call member function without object

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67952

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-10-13
            Summary|Compilation error with      |[C++14] Compilation error
                   |boost::signals2 and generic |with boost::signals2 and
                   |lambda: cannot call member  |generic lambda: cannot call
                   |function without object     |member function without
                   |                            |object
     Ever confirmed|0                           |1
      Known to fail|                            |4.9.3, 5.2.0, 6.0

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Nothing to do with Boost, so it doesn't need thousands of lines of Boost
headers to reproduce it:


template<typename F> struct signal;

template<typename R, typename... Args>
struct signal<R(Args...)>
{
  template<typename F>
    void connect(F f) { f( Args{}... ); }
};

class A
{
public:
    A()
    {
        // these two work
        sig2.connect( [this]() {f();} );
        sig.connect( [this](auto x) {this->g(x);} );

        // this does not work
        sig.connect( [this](auto x) {g(x);} );
    }


private:
    void f();
    void g(int);

    signal<void (int)> sig;
    signal<void ()> sig2;
};