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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Inkscape::Util::ptr_shared<T> - like T const *, but stronger.
+ * Used to hold c-style strings for objects that are managed by the gc.
+ *
+ * Authors:
+ * MenTaLguY <mental@rydia.net>
+ *
+ * Copyright (C) 2006 MenTaLguY
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_INKSCAPE_UTIL_SHARE_H
+#define SEEN_INKSCAPE_UTIL_SHARE_H
+
+#include "inkgc/gc-core.h"
+#include <cstring>
+#include <cstddef>
+
+namespace Inkscape {
+namespace Util {
+
+class ptr_shared {
+public:
+
+ ptr_shared() : _string(nullptr) {}
+ ptr_shared(ptr_shared const &other) = default;
+
+ operator char const *() const { return _string; }
+ operator bool() const { return _string; }
+
+ char const *pointer() const { return _string; }
+ char const &operator[](int i) const { return _string[i]; }
+
+ ptr_shared operator+(int i) const {
+ return share_unsafe(_string+i);
+ }
+ ptr_shared operator-(int i) const {
+ return share_unsafe(_string-i);
+ }
+ //WARNING: No bounds checking in += and -= functions. Moving the pointer
+ //past the end of the string and then back could probably cause the garbage
+ //collector to deallocate the string inbetween, as there's temporary no
+ //valid reference pointing into the allocated space.
+ ptr_shared &operator+=(int i) {
+ _string += i;
+ return *this;
+ }
+ ptr_shared &operator-=(int i) {
+ _string -= i;
+ return *this;
+ }
+ std::ptrdiff_t operator-(ptr_shared const &other) {
+ return _string - other._string;
+ }
+
+ ptr_shared &operator=(ptr_shared const &other) = default;
+
+ bool operator==(ptr_shared const &other) const {
+ return _string == other._string;
+ }
+ bool operator!=(ptr_shared const &other) const {
+ return _string != other._string;
+ }
+ bool operator>(ptr_shared const &other) const {
+ return _string > other._string;
+ }
+ bool operator<(ptr_shared const &other) const {
+ return _string < other._string;
+ }
+
+ friend ptr_shared share_unsafe(char const *string);
+
+private:
+ ptr_shared(char const *string) : _string(string) {}
+ static ptr_shared share_unsafe(char const *string) {
+ return ptr_shared(string);
+ }
+
+ //This class (and code using it) assumes that it never has to free this
+ //pointer, and that the memory it points to will not be freed as long as a
+ //ptr_shared pointing to it exists.
+ char const *_string;
+};
+
+ptr_shared share_string(char const *string);
+ptr_shared share_string(char const *string, std::size_t length);
+
+inline ptr_shared share_unsafe(char const *string) {
+ return ptr_shared::share_unsafe(string);
+}
+
+//TODO: Do we need this function?
+inline ptr_shared share_static_string(char const *string) {
+ return share_unsafe(string);
+}
+
+}
+}
+
+#endif
+/*
+ Local Variables:
+ mode:c++
+ c-file-style:"stroustrup"
+ c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+ indent-tabs-mode:nil
+ fill-column:99
+ End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :