ggab90@1130: /* -*- mode: C++; indent-tabs-mode: nil; -*-
ggab90@1130:  */
ggab90@1130: 
ggab90@1130: #ifndef STL_ITERATORS_H_
ggab90@1130: #define STL_ITERATORS_H_
ggab90@1130: 
ggab90@1130: #include <lemon/core.h>
ggab90@1130: 
ggab90@1130: namespace lemon {
ggab90@1130: 
ggab90@1130:   /// \brief Template to make STL iterators from Lemon iterators.
ggab90@1130:   ///
ggab90@1130:   /// This template makes an STL iterator from a Lemon iterator
ggab90@1130:   /// by adding the missing features.
ggab90@1130:   /// It inherits from \c std::iterator to make \c iterator_concept work
ggab90@1130:   /// (so that STL algorithms work).
ggab90@1130:   /// \c T should be the lemon iterator to be decorated.
ggab90@1130:   template<class T>
ggab90@1130:   struct LemonItWrapper
ggab90@1130:       : public T, public std::iterator<std::input_iterator_tag, T> {
ggab90@1130: 
ggab90@1130:     LemonItWrapper(const T &x) : T(x) {}
ggab90@1130: 
ggab90@1130:     //Lemon iterators don't have operator*, (because they rather
ggab90@1130:     //inherit from their "value_type"),
ggab90@1130:     //so we add one that just returns the object.
ggab90@1130:     const T& operator*() const {
ggab90@1130:       return static_cast<const T&>(*this);
ggab90@1130:     }
ggab90@1130: 
ggab90@1130:     //I can't think of any use case for this with Lemon iterators,
ggab90@1130:     //but maybe it should be included for completeness.
ggab90@1130:     const T* operator->() {
ggab90@1130:       return static_cast<const T*>(this);
ggab90@1130:     }
ggab90@1130: 
ggab90@1130:     //Lemon iterators don't have postincrement.
ggab90@1130:     void operator++(int) {
ggab90@1130:       T::operator++();
ggab90@1130:     }
ggab90@1130: 
ggab90@1130:     using T::operator++;
ggab90@1130: 
ggab90@1130:   };
ggab90@1130: 
ggab90@1130: 
ggab90@1130:   /// \brief A generic wrapper for Lemon iterators for range-based for loops.
ggab90@1130:   ///
ggab90@1130:   /// This template can be used to create a class
ggab90@1130:   /// that has begin() and end() from a Lemon iterator
ggab90@1130:   /// (with a 1-parameter constructor)
ggab90@1130:   /// to make range-based for loops and STL algorithms work.
ggab90@1130:   ///
ggab90@1130:   /// \c LIT is the Lemon iterator that will be wrapped
ggab90@1130:   /// \c P is the type of the parameter of the constructor of \c LIT.
ggab90@1130:   template<class LIT, class P>
ggab90@1130:   class LemonRangeWrapper1 {
ggab90@1130:     const P &_p;
ggab90@1130:     typedef LemonItWrapper<LIT> It;
ggab90@1130:   public:
ggab90@1130:     LemonRangeWrapper1(const P &p) : _p(p) {}
ggab90@1130:     It begin() const {
ggab90@1130:       return It(LIT(_p));
ggab90@1130:     }
ggab90@1130:     It end() const {
ggab90@1130:       return It(lemon::INVALID);
ggab90@1130:     }
ggab90@1130:   };
ggab90@1130: 
ggab90@1130: 
ggab90@1130:   /// \brief A generic wrapper for Lemon iterators for range-based for loops.
ggab90@1130:   ///
ggab90@1130:   /// This template can be used to create a class
ggab90@1130:   /// that has begin() and end() from a Lemon iterator
ggab90@1130:   /// (with a 2-parameter constructor)
ggab90@1130:   /// to make range-based for loops and STL algorithms work.
ggab90@1130:   ///
ggab90@1130:   /// \c LIT is the Lemon iterator that will be wrapped
ggab90@1130:   /// \c P1 and \c P2 are the types of the parameters
ggab90@1130:   /// of the constructor of \c LIT.
ggab90@1130:   template<class LIT, class P1, class P2>
ggab90@1130:   class LemonRangeWrapper2 {
ggab90@1130:     const P1 &_p1;
ggab90@1130:     const P2 &_p2;
ggab90@1130:     typedef LemonItWrapper<LIT> It;
ggab90@1130:   public:
ggab90@1130:     LemonRangeWrapper2(const P1 &p1, const P2 &p2) : _p1(p1), _p2(p2) {}
ggab90@1130:     It begin() const {
ggab90@1130:       return It(LIT(_p1, _p2));
ggab90@1130:     }
ggab90@1130:     It end() const {
ggab90@1130:       return It(lemon::INVALID);
ggab90@1130:     }
ggab90@1130:   };
ggab90@1130: 
ggab90@1130: 
ggab90@1130: }
ggab90@1130: 
ggab90@1130: #endif /* STL_ITERATORS_H_ */