Imported Upstream version 1.65.0upstream/1.65.0

Change-Id: Icf8400b375482cb11bcf77440a6934ba360d6ba4
Signed-off-by: DongHun Kwak <dh0128.kwak@samsung.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/boost/program_options/detail/value_semantic.hpp b/boost/program_options/detail/value_semantic.hpp
index 978a38a86e..9531339a34 100644
--- a/boost/program_options/detail/value_semantic.hpp
+++ b/boost/program_options/detail/value_semantic.hpp
@@ -8,6 +8,9 @@
 
 #include <boost/throw_exception.hpp>
 
+// forward declaration
+namespace boost { template<class T> class optional; }
+
 namespace boost { namespace program_options { 
 
     extern BOOST_PROGRAM_OPTIONS_DECL std::string arg;
@@ -152,6 +155,20 @@ namespace boost { namespace program_options {
         }
     }
 
+    /** Validates optional arguments. */
+    template<class T, class charT>
+    void validate(boost::any& v,
+                  const std::vector<std::basic_string<charT> >& s,
+                  boost::optional<T>*,
+                  int)
+    {
+        validators::check_first_occurrence(v);
+        validators::get_single_string(s);
+        boost::any a;
+        validate(a, s, (T*)0, 0);
+        v = boost::any(boost::optional<T>(boost::any_cast<T>(a)));
+    }
+
     template<class T, class charT>
     void 
     typed_value<T, charT>::