Fixed a typo in the spec for the is_empty() functions. I also added an

is_set() to the any_function so that it's interface is similar to the
member_function_pointer.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%404132

dlib/any/any_abstract.h

@@ -97,9 +97,9 @@ namespace dlib
         /*!
             ensures
                 - if (this object contains any kind of object) then
-                    - returns true
+                    - returns false 
                 - else
-                    - returns false
+                    - returns true 
         !*/
 
         template <typename T>

dlib/any/any_decision_function_abstract.h

@@ -93,9 +93,9 @@ namespace dlib
         /*!
             ensures
                 - if (this object contains any kind of object) then
-                    - returns true
+                    - returns false 
                 - else
-                    - returns false
+                    - returns true
         !*/
 
         scalar_type operator() (

dlib/any/any_function_abstract.h

@@ -119,9 +119,16 @@ namespace dlib
         /*!
             ensures
                 - if (this object contains any kind of object) then
-                    - returns true
+                    - returns false 
                 - else
-                    - returns false
+                    - returns true 
+        !*/
+
+        bool is_set (
+        ) const;
+        /*!
+            ensures
+                - returns !is_empty()
         !*/
 
         result_type operator() (

dlib/any/any_function_impl.h

@@ -69,6 +69,12 @@ bool is_empty(
     return data.get() == 0;
 }
 
+bool is_set(
+) const
+{
+    return !is_empty();
+}
+
 template <typename T>
 T& cast_to(
 ) 

dlib/any/any_trainer_abstract.h

@@ -103,9 +103,9 @@ namespace dlib
         /*!
             ensures
                 - if (this object contains any kind of object) then
-                    - returns true
+                    - returns false 
                 - else
-                    - returns false
+                    - returns true
         !*/
 
         trained_function_type train (