https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58407
Steinar H. Gunderson <steinar+gcc at gunderson dot no> changed:
What |Removed |Added
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CC| |steinar+gcc at gunderson dot no
--- Comment #17 from Steinar H. Gunderson <steinar+gcc at gunderson dot no> ---
Hi,
Does this change mean now it's effectively impossible to have abstract base
classes under -Wall without adding boilerplate? Consider something like the
following:
class Base {
public:
virtual ~Base() {}
virtual void foo() = 0;
};
class Derived : Base {
public:
~Derived();
void foo() override;
};
Base needs to have a virtual destructor since it has virtual member functions
(or half the world will give you warnings).
Any attempts now to copy Derived through the implicit copy constructor will
give a warning, since the synthesis of Base::Base(const Base &) is deprecated.
The only way I've found to suppress this is to add
Base::Base(const Base &) = default;
However, this in turn disables the synthesis of Base::Base(), and also
Base::operator=(const Base &). So I need:
Base() = default;
Base(const Base &) = default;
Base(Base &&) = default;
Base &operator= (const Base &) = default;
Base &operator= (Base &&) = default;
for something that doesn't have a single member!
Am I missing something?
