1.1 --- a/lemon/bits/utility.h	Thu Apr 19 15:11:58 2007 +0000
     1.2 +++ b/lemon/bits/utility.h	Thu Apr 19 15:12:59 2007 +0000
     1.3 @@ -83,6 +83,12 @@
     1.4    template<int T> struct dummy { dummy(int) {} };
     1.5  
     1.6    /**************** enable_if from BOOST ****************/
     1.7 +  
     1.8 +  template <typename Type, typename T = void>
     1.9 +  struct exists {
    1.10 +    typedef T type;
    1.11 +  };
    1.12 +
    1.13   
    1.14    template <bool B, class T = void>
    1.15    struct enable_if_c {