diff --git a/include/fc/array.hpp b/include/fc/array.hpp
index cd1f312..e82782b 100644
--- a/include/fc/array.hpp
+++ b/include/fc/array.hpp
@@ -32,6 +32,9 @@ namespace fc {
   template<typename T, size_t N>
   bool operator == ( const array<T,N>& a, const array<T,N>& b )
   { return 0 == memcmp( a.data, b.data, N*sizeof(T) ); }
+  template<typename T, size_t N>
+  bool operator < ( const array<T,N>& a, const array<T,N>& b )
+  { return  memcmp( a.data, b.data, N*sizeof(T) ) < 0 ; }
 
   template<typename T, size_t N>
   bool operator != ( const array<T,N>& a, const array<T,N>& b )