Index: TODO
===================================================================
diff -u -r1d6fce4237af2c0a77067e6cbf041bea2c30c37d -r46f5a635968d0c3dfe4c81f80e4ac21350096394
--- TODO	(.../TODO)	(revision 1d6fce4237af2c0a77067e6cbf041bea2c30c37d)
+++ TODO	(.../TODO)	(revision 46f5a635968d0c3dfe4c81f80e4ac21350096394)
@@ -5121,6 +5121,8 @@
 - added flag -nocomplain to "/obj/ /prop/ unset ?-nocomplain?"
 - use "mixin|filter clear" instead of "mixin|filter unset"
 - name parameter option "slotset" instead of "slotassign"
+- have "filter|mixin clear" return the list of former|removed
+  filters|mixins.
 
 nsfObj.c:
 - allow to omit "-guard" within arguments to flag
@@ -5136,24 +5138,6 @@
 
 - finish nx-property reform (merge into master)
 
-- IDEA: have "filter|mixin clear" return the list of former|removed
-  filters|mixins to stash them in the caller context. simplifies
-  turning on|off scenarios (one instead of two calls):
-
-  set tmp [obj object filter clear]
-  # ... do work ...
-  obj object filter $tmp
-
-  or: clear & check whether mixins|filters were set in one step:
-
-  if {[length [obj object filter clear]]} {
-    # ... there were actually filter active, now removed
-  } else {
-    # ... attempted clearing, but nothing active ...
-  }
-
-  or: a combination of the two idioms ...
-
 - check deactivated tests in tests/serialize.test
   C(One), C(IgnoreAll), C(None2)
   and xlloc fix
Index: library/nx/nx.tcl
===================================================================
diff -u -rf024f89a488f29a8745fcb928c6b7c94d0486d8f -r46f5a635968d0c3dfe4c81f80e4ac21350096394
--- library/nx/nx.tcl	(.../nx.tcl)	(revision f024f89a488f29a8745fcb928c6b7c94d0486d8f)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision 46f5a635968d0c3dfe4c81f80e4ac21350096394)
@@ -1519,7 +1519,9 @@
   ::nsf::method::alias RelationSlot value=get ::nsf::relation::get
 
   RelationSlot public method value=clear {obj prop} {
+    set result [::nsf::relation::set $obj $prop]
     ::nsf::relation::set $obj $prop {}
+    return $result
   }
 
   RelationSlot protected method delete_value {obj prop old value} {
Index: tests/interceptor-slot.test
===================================================================
diff -u -r24cc5e107fd8d246061a9d4b4fafefc767811c2b -r46f5a635968d0c3dfe4c81f80e4ac21350096394
--- tests/interceptor-slot.test	(.../interceptor-slot.test)	(revision 24cc5e107fd8d246061a9d4b4fafefc767811c2b)
+++ tests/interceptor-slot.test	(.../interceptor-slot.test)	(revision 46f5a635968d0c3dfe4c81f80e4ac21350096394)
@@ -27,7 +27,7 @@
   ? {C info mixin classes} ""
 
   ? {C mixin set ::M} "::M"
-  ? {C mixin clear} ""
+  ? {C mixin clear} "::M"
   ? {C info mixin classes} ""
 
   ? {C mixin add ::M} "::M"
@@ -69,7 +69,7 @@
 
   ? {c1 object mixin add M} {::M}
   ? {c1 info object mixin classes} {::M}
-  ? {c1 object mixin clear} {}
+  ? {c1 object mixin clear} {::M}
   ? {c1 info object mixin classes} {}
 }
 
@@ -196,7 +196,7 @@
   ? {::nsf::relation::get CC object-filter} "filterC"
   ? {CC info object filter methods} "filterC"
 
-  ? {CC object filter clear} ""
+  ? {CC object filter clear} "filterC"
   ? {::nsf::relation::get CC object-filter} ""
   ? {CC info object filter methods} ""
   
@@ -218,7 +218,7 @@
   ? {::nsf::relation::get CC class-filter} "filterB"
   ? {CC info filter methods} "filterB"
 
-  ? {CC filter clear} ""
+  ? {CC filter clear} "filterB"
   ? {::nsf::relation::get CC class-filter} ""
   ? {CC info filter methods} ""
 }