add ListWrapper<T,E>. define StringPairList.

src/types.hh

@@ -21,6 +21,7 @@ namespace pEp
 
     using Identity = Wrapper<::pEp_identity*>;
     using StringPair = Wrapper<::stringpair_t*>;
+    using StringPairList = ListWrapper<::stringpair_list_t*, ::stringpair_t*>;
     
     using Message = Wrapper<::message*>;
 

src/wrapper.hh

@@ -4,6 +4,8 @@
 #ifndef LIBPEPDATATYPES_WRAPPER_HH
 #define LIBPEPDATATYPES_WRAPPER_HH
 
+#include <initializer_list>
+
 namespace pEp
 {
 
@@ -69,7 +71,10 @@ public:
     }
     
 
-private:
+protected:
+
+    Wrapper(T* _value) : value{_value} {}
+
     // must be defined for each wrapped type:
     template<class... Args>
     T* _new(Args...);
@@ -80,6 +85,44 @@ private:
 };
 
 
+// Wraps single-linked lists and provides an interface compatible
+// to std::forward_list
+template<class T, class Element>
+class ListWrapper;
+
+
+template<class T, class Element>
+class ListWrapper<T*, Element> : public Wrapper<T*>
+{
+public:
+    struct Trait;
+    typedef Wrapper<T*> Base;
+    typedef ListWrapper<T*, Element> iterator; // FIXME: different type necessary?
+    
+    static Element T::* const Value; // to access the current value
+    
+    using Base::Base;
+    using Base::value;
+    
+    ListWrapper() : Base() {}
+    ListWrapper(const std::initializer_list<Element>& i);
+    
+    iterator begin()     { return value; }
+    iterator end() const { return iterator{}; }
+    int  size()    const;
+    bool empty()   const;
+    
+    // I am my own iterator
+    iterator operator++() { return (value ? value = value->next : value); }
+    Element  operator*()  { return value->Value; }
+    
+    void clear();
+    void push_back(Element&&);
+    
+};
+
+
+
 } // end of namespace pEp
 
 #endif // LIBPEPDATATYPES_WRAPPER_HH