[Bug c++/64615] Access level check error: g++ thinks the non default ctor is protected while its public

[Bug c++/64615] Access level check error: g++ thinks the non default ctor is protected while its public

[petschy at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64615

--- Comment #1 from petschy at gmail dot com ---
Created attachment 34457
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34457&action=edit
complete test case

[Bug c++/64615] Access level check error: g++ thinks the non default ctor is protected while its public

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64615

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |UNCONFIRMED
     Ever confirmed|1                           |0

[Bug c++/64615] Access level check error: g++ thinks the non default ctor is protected while its public

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64615

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
clang rejects this code with a similar error message as gcc.

[Bug c++/64615] Access level check error: g++ thinks the non default ctor is protected while its public

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64615

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The standard is clear that D::D(int) is protected:

"Base-class constructors considered because of a using-declarator are
accessible if they would be accessible when used to construct an object of the
base class; the accessibility of the using-declaration is ignored."

So G++ is correct to give an error on that line.

I'm not sure why D::D() is public though. It seems that it isn't inherited from
B::B() but is implicitly defined by the compiler (and then calls B::B() but
it's OK for D's constructor to call the protected constructor of its base
class).

[Bug c++/64615] Access level check error: g++ thinks the non default ctor is protected while its public

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64615

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |INVALID
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The standard says:

"If there is no user-declared constructor for class X, a non-explicit
constructor having no parameters is implicitly declared as defaulted"

An inherited constructor is not user-declared, so D still gets an
implicitly-declared:

  D() = default;

This is public, and can call the protected B() constructor.

So G++ is correct.