From b4e3e99cc8efb18c9de236a42e195b6b509917ba Mon Sep 17 00:00:00 2001
From: Norman Feske <norman.feske@genode-labs.com>
Date: Tue, 18 Aug 2015 15:29:38 +0200
Subject: [PATCH] base: add Weak_object::weak_ptr const

Issue #1649
---
 repos/base/include/base/weak_ptr.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/repos/base/include/base/weak_ptr.h b/repos/base/include/base/weak_ptr.h
index 79d60c2d2..0290cf48e 100644
--- a/repos/base/include/base/weak_ptr.h
+++ b/repos/base/include/base/weak_ptr.h
@@ -290,6 +290,22 @@ struct Genode::Weak_object : Genode::Weak_object_base
 	 * Obtain a weak pointer referring to the weak object
 	 */
 	Weak_ptr<T> weak_ptr() { return _weak_ptr<T>(); }
+
+	/**
+	 * Const version of 'weak_ptr'
+	 *
+	 * This function is useful in cases where the returned weak pointer is
+	 * merely used for comparison operations.
+	 */
+	Weak_ptr<T const> const weak_ptr_const() const
+	{
+		/*
+		 * We strip off the constness of 'this' to reuse the internal non-const
+		 * code of the weak object. The executed operations are known to not
+		 * alter the state of the weak object.
+		 */
+		return const_cast<Weak_object *>(this)->_weak_ptr<T const>();
+	}
 };