From 358745d7ded0492cc8c61fa46d7c0928f584c184 Mon Sep 17 00:00:00 2001
From: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Date: Tue, 24 Oct 2023 21:13:36 +0200
Subject: QSP/QWP: introduce owner_before, owner_equal, owner_hash

While at the moment we don't have aliasing support in QSharedPointer,
introduce owner-based comparisons and hashing. This also fulfills some
use cases in lieu of operator== for QWeakPointer (which got deprecated
by bb23a05905d7dc0e416a646e40592436daa939f2).

I'm using C++26/P1901's spelling of owner_equal, instead of
Boost.SmartPtr's spelling (owner_equal*s*). Given the niche use case,
the lack of interoperability with Qt's own containers, as well as the
Standard comparison objects' semantics (std::owner_less,
std::owner_equal), I don't think we should be giving these a Qt-ish name
as it would be pretty useless.

[ChangeLog][QtCore][QSharedPointer] Added owner_before, owner_equal,
owner_hash.
[ChangeLog][QtCore][QWeakPointer] Added owner_before, owner_equal,
owner_hash.

Done-with: Fabian Kosmale <fabian.kosmale@qt.io>
Change-Id: I8b792ae79f14cd518ba4a006edaa17786a8352a0
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
---
 src/corelib/tools/qsharedpointer.h | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

(limited to 'src/corelib/tools/qsharedpointer.h')

diff --git a/src/corelib/tools/qsharedpointer.h b/src/corelib/tools/qsharedpointer.h
index 2a60f3ca5e..116c9afa00 100644
--- a/src/corelib/tools/qsharedpointer.h
+++ b/src/corelib/tools/qsharedpointer.h
@@ -72,6 +72,19 @@ public:
 
     template <typename... Args>
     static inline QSharedPointer<T> create(Args &&... args);
+
+    // owner-based comparisons
+    template <typename X>
+    bool owner_before(const QSharedPointer<X> &other) const noexcept;
+    template <typename X>
+    bool owner_before(const QWeakPointer<X> &other) const noexcept;
+
+    template <typename X>
+    bool owner_equal(const QSharedPointer<X> &other) const noexcept;
+    template <typename X>
+    bool owner_equal(const QWeakPointer<X> &other) const noexcept;
+
+    size_t owner_hash() const noexcept;
 };
 
 template <class T>
@@ -108,6 +121,19 @@ public:
 
     QSharedPointer<T> toStrongRef() const;
     QSharedPointer<T> lock() const;
+
+    // owner-based comparisons
+    template <typename X>
+    bool owner_before(const QWeakPointer<X> &other) const noexcept;
+    template <typename X>
+    bool owner_before(const QSharedPointer<X> &other) const noexcept;
+
+    template <typename X>
+    bool owner_equal(const QWeakPointer<X> &other) const noexcept;
+    template <typename X>
+    bool owner_equal(const QSharedPointer<X> &other) const noexcept;
+
+    size_t owner_hash() const noexcept;
 };
 
 template <class T>
-- 
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