Add swap() and support std::hash

include/rcp.h

@@ -23,6 +23,7 @@
 #pragma once
 
 #include <atomic>
+#include <functional>
 #include <type_traits>
 
 /**
@@ -118,6 +119,13 @@ public:
         other.ptr = nullptr;
     }
 
+    void swap(rcp & other) noexcept
+    {
+        T * tmp = ptr;
+        ptr = other.ptr;
+        other.ptr = tmp;
+    }
+
     void reset()
     {
         if (ptr)
@@ -179,6 +187,18 @@ public:
     friend rcp<V> rcp_dynamic_cast(rcp<W> && other);
 };
 
+namespace std
+{
+    template <typename T>
+    struct hash<rcp<T>>
+    {
+        size_t operator()(const rcp<T> & p) const noexcept
+        {
+            return hash<const void *>()(static_cast<const void *>(p.get_raw()));
+        }
+    };
+}
+
 template <typename T, typename U>
 rcp<T> rcp_dynamic_cast(const rcp<U> & other)
 {

tests.cpp

@@ -1,5 +1,6 @@
 #include <rcp.h>
 #include <cassert>
+#include <unordered_map>
 #include <vector>
 
 static int mybase_construct;
@@ -313,6 +314,26 @@ protected:
     ~Counter() { external_destruct++; }
 };
 
+void test_swap()
+{
+    MyB a = MyB::create(1, 2);
+    MyB b = MyB::create(3, 4);
+    a.swap(b);
+    assert(a->x == 3);
+    assert(b->x == 1);
+}
+
+void test_hash()
+{
+    MyB a = MyB::create(1, 2);
+    MyB b = a;
+    std::unordered_map<MyB, int> map;
+    map[a] = 42;
+    assert(map[b] == 42);
+    MyB c = MyB::create(3, 4);
+    assert(map.find(c) == map.end());
+}
+
 void test_external_class()
 {
     int before = external_destruct;
@@ -347,6 +368,8 @@ int main(int argc, char * argv[])
     test_dynamic_cast_failure();
     test_dynamic_cast_move_success();
     test_dynamic_cast_move_failure();
+    test_swap();
+    test_hash();
     test_external_class();
     return 0;
 }