Merge pull request #51 from EricMCornelius/master

Use type_traits to enable Packet& sniff_loop callback variant in C++11

include/tins/internals.h

@@ -30,6 +30,10 @@
 #ifndef TINS_INTERNALS_H
 #define TINS_INTERNALS_H
 
+#if TINS_IS_CXX11
+#include <type_traits>
+#endif
+
 #include <sstream>
 #include <string>
 #include <stdint.h>
@@ -200,6 +204,39 @@ template<>
 struct is_unsigned_integral<uint64_t> {
     static const bool value = true;
 };
+
+#if TINS_IS_CXX11
+
+// Part of C++14 standard library
+template<bool B, class T = void>
+using enable_if_t = typename std::enable_if<B,T>::type;
+
+// Template metaprogramming trait to determine if a functor can accept another parameter as an argument
+template <class T, class P, class=void>
+struct accepts_type : std::false_type { };
+
+template <class T, class P>
+struct accepts_type<T, P, enable_if_t<
+  std::is_same<  decltype(  std::declval<T>()(std::declval<P>())  ), bool>::value
+>> : std::true_type { };
+
+// use enable_if to invoke the Packet&& version of the sniff_loop handler if possible - otherwise fail to old behavior
+template <class Functor, class Packet>
+bool invoke_loop_cb(Functor& f, Packet& p, typename std::enable_if<accepts_type<Functor, Packet>::value, bool>::type* = 0) {
+  return f(std::move(p));
+}
+
+template <class Functor, class Packet>
+bool invoke_loop_cb(Functor& f, Packet& p, typename std::enable_if<!accepts_type<Functor, Packet>::value && accepts_type<Functor, Packet&>::value, bool>::type* = 0) {
+  return f(p);
+}
+
+template <class Functor, class Packet>
+bool invoke_loop_cb(Functor& f, Packet& p, typename std::enable_if<!accepts_type<Functor, Packet>::value && !accepts_type<Functor, Packet&>::value, bool>::type* = 0) {
+  return f(*p.pdu());
+}
+#endif
+
 } // namespace Internals
 } // namespace Tins
 /**

include/tins/sniffer.h

@@ -139,6 +139,9 @@ namespace Tins {
          * \code
          * bool(PDU&);
          * bool(const PDU&);
+         * bool(const Packet&);
+         * bool(Packet&&);
+         * bool(Packet);
          * \endcode
          *
          * This functor will be called using the each of the sniffed packets
@@ -391,7 +394,7 @@ namespace Tins {
     /**
      * \brief Iterates over packets sniffed by a BaseSniffer.
      */
-    class SnifferIterator : public std::iterator<std::forward_iterator_tag, PDU> {
+    class SnifferIterator : public std::iterator<std::forward_iterator_tag, Packet> {
     public:
         /**
          * Constructs a SnifferIterator.
@@ -425,15 +428,15 @@ namespace Tins {
          * Dereferences the iterator.
          * \return reference to the current packet.
          */
-        PDU &operator*() {
-            return *pkt.pdu();
+        Packet &operator*() {
+            return pkt;
         }
 
         /**
          * Dereferences the iterator.
          * \return pointer to the current packet.
          */
-        PDU *operator->() {
+        Packet *operator->() {
             return &(**this);
         }
 
@@ -578,8 +581,13 @@ namespace Tins {
         for(iterator it = begin(); it != end(); ++it) {
             try {
                 // If the functor returns false, we're done
-                if(!function(*it))
+                #if TINS_IS_CXX11
+                if (!Tins::Internals::invoke_loop_cb(function, *it))
                     return;
+                #else
+                if(!function(*it->pdu()))
+                    return;
+                #endif
             }
             catch(malformed_packet&) { }
             catch(pdu_not_found&) { }