gc-anchored.h

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Authors:
 *   MenTaLguY <mental@rydia.net>
 * * Copyright (C) 2004 MenTaLguY
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
 
#ifndef SEEN_INKSCAPE_GC_ANCHORED_H
#define SEEN_INKSCAPE_GC_ANCHORED_H
 
#include "inkgc/gc-managed.h"
 
namespace Inkscape::GC {
 
class Anchored {
public:
    void anchor() const;
    void release() const;
 
    // for debugging
    unsigned _anchored_refcount() const {
        return ( _anchor ? _anchor->refcount : 0 );
    }
 
    Anchored(Anchored const &) = delete; // no copy
    void operator=(Anchored const &) = delete; // no assign
 
protected:
    Anchored() : _anchor(nullptr) { anchor(); } // initial refcount of one
    virtual ~Anchored() = default;
 
private:
    struct Anchor : public Managed<SCANNED, MANUAL> {
        Anchor() : refcount(0),base(nullptr) {}
        Anchor(Anchored const *obj) : refcount(0) {
            base = Core::base(const_cast<Anchored *>(obj));
        }
        int refcount;
        void *base;
    };
 
    mutable Anchor *_anchor;
 
    Anchor *_new_anchor() const;
    void _free_anchor(Anchor *anchor) const;
};
 
template <typename R>
static R &anchor(R &r) {
    static_cast<Anchored const &>(const_cast<R const &>(r)).anchor();
    return r;
}
 
template <typename R>
static R *anchor(R *r) {
    static_cast<Anchored const *>(const_cast<R const *>(r))->anchor();
    return r;
}
 
template <typename R>
static R &release(R &r) {
    static_cast<Anchored const &>(const_cast<R const &>(r)).release();
    return r;
}
 
template <typename R>
static R *release(R *r) {
    static_cast<Anchored const *>(const_cast<R const *>(r))->release();
    return r;
}
 
} // namespace Inkscape::GC
 
#endif // SEEN_INKSCAPE_GC_ANCHORED_H
 
/*
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  mode:c++
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  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
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  End:
*/
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