Moved basic_type out of any and made it a first class object with

proper documentation.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%404035

dlib/algs.h

@@ -630,6 +630,25 @@ namespace dlib
     template <typename T> inline typename disable_if<is_built_in_scalar_type<T>,void>::type assign_zero_if_built_in_scalar_type (T&){}
     template <typename T> inline typename enable_if<is_built_in_scalar_type<T>,void>::type assign_zero_if_built_in_scalar_type (T& a){a=0;}
 
+// ----------------------------------------------------------------------------------------
+
+    /*!A basic_type
+
+        This is a template that takes a type and trips off any const, volatile, or reference
+        qualifiers and gives you back the basic underlying type.  So for example:
+
+        basic_type<const int&>::type == int
+    !*/
+
+    template <typename T> struct basic_type { typedef T type; };
+    template <typename T> struct basic_type<const T> { typedef T type; };
+    template <typename T> struct basic_type<const T&> { typedef T type; };
+    template <typename T> struct basic_type<volatile const T&> { typedef T type; };
+    template <typename T> struct basic_type<T&> { typedef T type; };
+    template <typename T> struct basic_type<volatile T&> { typedef T type; };
+    template <typename T> struct basic_type<volatile T> { typedef T type; };
+    template <typename T> struct basic_type<volatile const T> { typedef T type; };
+
 // ----------------------------------------------------------------------------------------
 
     template <typename T>

dlib/any/any.h

@@ -25,14 +25,6 @@ namespace dlib
 
     class any
     {
-        template <typename T> struct basic_type { typedef T type; };
-        template <typename T> struct basic_type<const T> { typedef T type; };
-        template <typename T> struct basic_type<const T&> { typedef T type; };
-        template <typename T> struct basic_type<volatile const T&> { typedef T type; };
-        template <typename T> struct basic_type<T&> { typedef T type; };
-        template <typename T> struct basic_type<volatile T&> { typedef T type; };
-        template <typename T> struct basic_type<volatile T> { typedef T type; };
-        template <typename T> struct basic_type<volatile const T> { typedef T type; };
 
     public: