On Wed, 1 Jul 2026, 06:15 Rainer Deyke via Std-Proposals, <
std-proposals_at_[hidden]> wrote:

>
>
> On 6/30/26 18:18, Ruud Rietvink via Std-Proposals wrote:
> > Proposal is to introduce an initializer method that is automatically
> > called after the construction is complete,
> > and a finalizer method that is automatically called before the
> > destruction of an object.
> > Because the finalizer is called before the destructing, the vtable is
> > still correct and virtual calling will work correctly.
> > Proposed names:
> > class::+class() for initializing
> > class::-class() for finalizing
>
> This solves a real problem, but I am not convinced that it solves it
> better than the idiomatic workaround, nor that the problem is common
> enough to justify a change in the language. The idiomatic workaround:
>
> class base {
> public:
> base(int) { this->init(); }
> protected:
> base() = default;
> virtual void f() {}
> void init() {
> this->f();
> }
> };
>
> class derived1 : public base {
> public:
> derived1(int n) : base(n) {
>

Checking I understand the idiom you're describing:
Is this meant to call base() to avoid using init() twice?

       this->init();
> }
> protected:
> derived1() = default;
> void f() override {}
> };
>
> class derived2 final : public base {
> public:
> derived2(int n) : derived1(n) {
>

And same here?

       this->init();
> }
> protected:
> void f() override {}
> }
>
> Obviously this idiom is not perfect. The base class needs an additional
> protected constructor that can't come into overload conflict with the
> other constructors. All derived classes need to remember to call init.
> It requires more typing. But this extra typing buys you quite a bit of
> extra flexibility:
> - You can pass arguments to `init`.
> - You can overload `init`.
> - You can put additional statements in your constructor after `init`.
> - You can choose *not* to call `init` for some constructors.
>
> The last two bits of flexibility might be controversial, but the first
> two shouldn't be. When I use this idiom, I *usually* end up needing
> arguments from the constructor for what I do in `init`.
>
>
> --
> Rainer Deyke - rainerd_at_[hidden]
> --
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>