Put back std::type_info.

Since typed_value_base is only used with RTTI on, there's
no need to avoid std::type_info there.

Author: vprus

include/boost/program_options/value_semantic.hpp

@@ -175,7 +175,7 @@ namespace boost { namespace program_options {
     public:
         // Returns the type of the value described by this
         // object.
-        virtual const boost::typeindex::type_info& value_type() const = 0;
+        virtual const std::type_info& value_type() const = 0;
         // Not really needed, since deletion from this
         // class is silly, but just in case.
         virtual ~typed_value_base() {}
@@ -366,7 +366,7 @@ namespace boost { namespace program_options {
 #ifndef BOOST_NO_RTTI
         const boost::typeindex::type_info& value_type() const
         {
-            return boost::typeindex::type_id<T>().type_info();
+            return typeid(T);
         }
 #endif