util/DeleteDisposer: new utility class

Makefile.am

@@ -391,6 +391,7 @@ libutil_a_SOURCES = \
 	src/util/Macros.hxx \
 	src/util/Cast.hxx \
 	src/util/Clamp.hxx \
+	src/util/DeleteDisposer.hxx \
 	src/util/Alloc.cxx src/util/Alloc.hxx \
 	src/util/VarSize.hxx \
 	src/util/Error.cxx src/util/Error.hxx \

src/client/Client.hxx

@@ -51,12 +51,6 @@ public:
 	struct playlist &playlist;
 	struct PlayerControl &player_control;
 
-	struct Disposer {
-		void operator()(Client *client) const {
-			delete client;
-		}
-	};
-
 	unsigned permission;
 
 	/** the uid of the client process, or -1 if unknown */

src/client/ClientList.cxx

@@ -20,8 +20,7 @@
 #include "config.h"
 #include "ClientList.hxx"
 #include "ClientInternal.hxx"
-
-#include <algorithm>
+#include "util/DeleteDisposer.hxx"
 
 #include <assert.h>
 
@@ -36,7 +35,7 @@ ClientList::Remove(Client &client)
 void
 ClientList::CloseAll()
 {
-	list.clear_and_dispose(Client::Disposer());
+	list.clear_and_dispose(DeleteDisposer());
 }
 
 void

src/db/plugins/simple/Directory.cxx

@@ -31,6 +31,7 @@
 #include "lib/icu/Collate.hxx"
 #include "fs/Traits.hxx"
 #include "util/Alloc.hxx"
+#include "util/DeleteDisposer.hxx"
 #include "util/Error.hxx"
 
 #include <assert.h>
@@ -51,7 +52,7 @@ Directory::~Directory()
 	delete mounted_database;
 
 	songs.clear_and_dispose(Song::Disposer());
-	children.clear_and_dispose(Disposer());
+	children.clear_and_dispose(DeleteDisposer());
 }
 
 void
@@ -61,7 +62,7 @@ Directory::Delete()
 	assert(parent != nullptr);
 
 	parent->children.erase_and_dispose(parent->children.iterator_to(*this),
-					   Disposer());
+					   DeleteDisposer());
 }
 
 const char *
@@ -110,7 +111,8 @@ Directory::PruneEmpty()
 		child->PruneEmpty();
 
 		if (child->IsEmpty())
-			child = children.erase_and_dispose(child, Disposer());
+			child = children.erase_and_dispose(child,
+							   DeleteDisposer());
 		else
 			++child;
 	}

src/db/plugins/simple/Directory.hxx

@@ -53,12 +53,6 @@ struct Directory {
 	typedef boost::intrusive::link_mode<link_mode> LinkMode;
 	typedef boost::intrusive::list_member_hook<LinkMode> Hook;
 
-	struct Disposer {
-		void operator()(Directory *directory) const {
-			delete directory;
-		}
-	};
-
 	/**
 	 * Pointers to the siblings of this directory within the
 	 * parent directory.  It is unused (undefined) in the root

src/lib/nfs/Manager.cxx

@@ -21,6 +21,7 @@
 #include "Manager.hxx"
 #include "event/Loop.hxx"
 #include "Log.hxx"
+#include "util/DeleteDisposer.hxx"
 
 #include <string.h>
 
@@ -65,9 +66,7 @@ NfsManager::~NfsManager()
 
 	CollectGarbage();
 
-	connections.clear_and_dispose([](ManagedConnection *c){
-			delete c;
-		});
+	connections.clear_and_dispose(DeleteDisposer());
 }
 
 NfsConnection &
@@ -95,9 +94,7 @@ NfsManager::CollectGarbage()
 {
 	assert(GetEventLoop().IsInside());
 
-	garbage.clear_and_dispose([](ManagedConnection *c){
-			delete c;
-		});
+	garbage.clear_and_dispose(DeleteDisposer());
 }
 
 void

src/util/DeleteDisposer.hxx

+/*
+ * Copyright (C) 2015 Max Kellermann <max@duempel.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef DELETE_DISPOSER_HXX
+#define DELETE_DISPOSER_HXX
+
+/**
+ * A disposer for boost::intrusive that invokes the "delete" operator
+ * on the given pointer.
+ */
+struct DeleteDisposer {
+	template<typename T>
+	void operator()(T *t) {
+		delete t;
+	}
+};
+
+#endif