move AnyArity default arity checker

alib2std/src/extensions/forward_tree.hpp

@@ -10,14 +10,6 @@
 namespace std {
-/*template < class T >
-struct AnyArity {
-	bool operator ()( const T &, unsigned ) const {
-		return true;
-	}
-
-};*/
-
 template < class T, class ArityChecker = AnyArity < T > >
 class forward_tree {

alib2std/src/extensions/tree.hpp

@@ -10,14 +10,6 @@
 namespace std {
-template < class T >
-struct AnyArity {
-	bool operator ()( const T &, unsigned ) const {
-		return true;
-	}
-
-};
-
 template < class T, class ArityChecker = AnyArity < T > >
 class tree {

alib2std/src/extensions/tree_base.hpp

@@ -10,6 +10,14 @@
 namespace std {
+template < class T >
+struct AnyArity {
+	bool operator ()( const T &, unsigned ) const {
+		return true;
+	}
+
+};
+
 template < class Data >
 class BaseNode {
 	Data * parent;