1.1 --- a/src/lemon/utility.h	Sat May 14 17:29:28 2005 +0000
     1.2 +++ b/src/lemon/utility.h	Sat May 14 17:32:11 2005 +0000
     1.3 @@ -107,6 +107,47 @@
     1.4    template <class Cond, class T> 
     1.5    struct lazy_disable_if : public lazy_disable_if_c<Cond::value, T> {};
     1.6  
     1.7 +  // smart referencing
     1.8 +
     1.9 +  template <typename _Type, typename Enable = void>
    1.10 +  struct SmartReference {
    1.11 +    typedef _Type& Type;
    1.12 +  };
    1.13 +  
    1.14 +  template <typename _Type>
    1.15 +  struct SmartReference<
    1.16 +    _Type, 
    1.17 +    typename enable_if<typename _Type::NeedCopy, void>::type
    1.18 +  > {
    1.19 +    typedef _Type Type;
    1.20 +  };
    1.21 +
    1.22 +  template <typename _Type, typename Enable = void>
    1.23 +  struct SmartConstReference {
    1.24 +    typedef const _Type& Type;
    1.25 +  };
    1.26 +  
    1.27 +  template <typename _Type>
    1.28 +  struct SmartConstReference<
    1.29 +    _Type, 
    1.30 +    typename enable_if<typename _Type::NeedCopy, void>::type
    1.31 +  > {
    1.32 +    typedef const _Type Type;
    1.33 +  };
    1.34 +
    1.35 +  template <typename _Type, typename Enable = void>
    1.36 +  struct SmartParameter {
    1.37 +    typedef _Type& Type;
    1.38 +  };
    1.39 +  
    1.40 +  template <typename _Type>
    1.41 +  struct SmartParameter<
    1.42 +    _Type, 
    1.43 +    typename enable_if<typename _Type::NeedCopy, void>::type
    1.44 +  > {
    1.45 +    typedef const _Type& Type;
    1.46 +  };
    1.47 +
    1.48  } // namespace lemon
    1.49  
    1.50  #endif