- singleton: added equality operators & allow copy constructor.

Author: svdev

include/creational/singleton.hpp

@@ -18,9 +18,18 @@ template<typename T>
 class singleton {
 
 public:
-    singleton(const singleton<T>&) = delete;
+    singleton(const singleton<T>&) = default;
     singleton& operator=(const singleton<T>&) = delete;
 
+    template <typename U>
+    inline bool operator==(const U& rhs) const {
+        return std::is_same<T,U>::value;
+    }
+    template <typename U>
+    inline bool operator!=(const U& rhs) const {
+        return !(*this == rhs);
+    }
+
 protected:
     singleton()
     {

test/creational/singleton.cpp

@@ -17,12 +17,33 @@ class my_singleton : public dpc::singleton<my_singleton> {
 
 TEST(DessignPatternSingletonTest, SingletonInstantiation)
 {
-    my_singleton a;
+    auto a = my_singleton::get();
     my_singleton b;
 
+    ASSERT_FALSE(std::addressof(a) == std::addressof(b));
+    ASSERT_TRUE(std::addressof(*a) == std::addressof(*b));
+    ASSERT_TRUE(std::addressof(a.get()) == std::addressof(b.get()));
     ASSERT_STREQ(a->instance_addr().c_str(), b->instance_addr().c_str());
-    ASSERT_STREQ(my_singleton::get().instance_addr().c_str(),
-                 a->instance_addr().c_str());
+}
+
+TEST(DessignPatternSingletonTest, SingletonEquality)
+{
+    my_singleton a;
+    my_singleton b;
+
+    ASSERT_EQ(a, b);
+}
+
+TEST(DessignPatternSingletonTest, SingletonNotEquality)
+{
+    my_singleton a;
+
+    class my_class {};
+    my_class b;
+    int c = 0;
+
+    ASSERT_TRUE(a != b);
+    ASSERT_TRUE(a != c);
 }
 
 int main(int argc, char **argv) {