Added missing declaration for int64 in the is_built_in_scalar_type template.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403966

dlib/algs.h

@@ -585,6 +585,7 @@ namespace dlib
     template <> struct is_built_in_scalar_type<unsigned int>    { const static bool value = true; };
     template <> struct is_built_in_scalar_type<unsigned long>   { const static bool value = true; };
     template <> struct is_built_in_scalar_type<uint64>          { const static bool value = true; };
+    template <> struct is_built_in_scalar_type<int64>           { const static bool value = true; };
     template <> struct is_built_in_scalar_type<char>            { const static bool value = true; };
     template <> struct is_built_in_scalar_type<signed char>     { const static bool value = true; };
     template <> struct is_built_in_scalar_type<unsigned char>   { const static bool value = true; };