diff --git a/libs/ardour/audio_unit.cc b/libs/ardour/audio_unit.cc
index 20a55e49f9..e43033eb67 100644
--- a/libs/ardour/audio_unit.cc
+++ b/libs/ardour/audio_unit.cc
@@ -1824,7 +1824,6 @@ AUPlugin::do_save_preset (string preset_name)
 	CFPropertyListRef propertyList;
 	vector<Glib::ustring> v;
 	Glib::ustring user_preset_path;
-	bool ret = true;
 
 	std::string m = maker();
 	std::string n = name();
@@ -1843,12 +1842,12 @@ AUPlugin::do_save_preset (string preset_name)
 
 	if (g_mkdir_with_parents (user_preset_path.c_str(), 0775) < 0) {
 		error << string_compose (_("Cannot create user plugin presets folder (%1)"), user_preset_path) << endmsg;
-		return false;
+		return string();
 	}
 
 	DEBUG_TRACE (DEBUG::AudioUnits, "get current preset\n");
 	if (unit->GetAUPreset (propertyList) != noErr) {
-		return false;
+		return string();
 	}
 
 	// add the actual preset name */
@@ -1863,7 +1862,7 @@ AUPlugin::do_save_preset (string preset_name)
 
 	if (save_property_list (propertyList, user_preset_path)) {
 		error << string_compose (_("Saving plugin state to %1 failed"), user_preset_path) << endmsg;
-		ret = false;
+		return string();
 	}
 
 	CFRelease(propertyList);
diff --git a/libs/ardour/audiosource.cc b/libs/ardour/audiosource.cc
index 74dd52d504..84a5b687f9 100644
--- a/libs/ardour/audiosource.cc
+++ b/libs/ardour/audiosource.cc
@@ -182,7 +182,7 @@ AudioSource::touch_peakfile ()
 	struct utimbuf tbuf;
 
 	tbuf.actime = statbuf.st_atime;
-	tbuf.modtime = time ((time_t) 0);
+	tbuf.modtime = time ((time_t*) 0);
 
 	utime (peakpath.c_str(), &tbuf);
 }
diff --git a/libs/pbd/pbd/stl_delete.h b/libs/pbd/pbd/stl_delete.h
index ac2161560c..bca0ea9e21 100644
--- a/libs/pbd/pbd/stl_delete.h
+++ b/libs/pbd/pbd/stl_delete.h
@@ -21,17 +21,10 @@
 #define __libmisc_stl_delete_h__
 
 
-#if __clang__ && __APPLE__ && __cplusplus >= 201103L
-#include <vector>
-#ifndef _CPP_VECTOR
-#define _CPP_VECTOR
-#endif
-#endif
-
 /* To actually use any of these deletion functions, you need to
    first include the revelant container type header.
 */
-#if defined(_CPP_VECTOR) || defined(_GLIBCXX_VECTOR) || defined(__SGI_STL_VECTOR)
+#if defined(_CPP_VECTOR) || defined(_GLIBCXX_VECTOR) || defined(__SGI_STL_VECTOR) || defined(_LIBCPP_VECTOR)
 template<class T> void vector_delete (std::vector<T *> *vec)
 {
 	typename std::vector<T *>::iterator i;
@@ -41,7 +34,7 @@ template<class T> void vector_delete (std::vector<T *> *vec)
 	}
 	vec->clear ();
 }
-#endif // _CPP_VECTOR || _GLIBCXX_VECTOR || __SGI_STL_VECTOR
+#endif // _CPP_VECTOR || _GLIBCXX_VECTOR || __SGI_STL_VECTOR || _LIBCPP_VECTOR
 
 #if defined(_CPP_MAP) || defined(_GLIBCXX_MAP) || defined(__SGI_STL_MAP)
 template<class K, class T> void map_delete (std::map<K, T *> *m)