Add unique_ptr example to test the use of rvalue references. I'll grow

this example further as more rvalue-reference features come online.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123980 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/SemaCXX/rval-references-examples.cpp b/test/SemaCXX/rval-references-examples.cpp
new file mode 100644 (file)
index 0000000..1cde585
--- /dev/null
+++ b/test/SemaCXX/rval-references-examples.cpp
@@ -0,0 +1,88 @@
+// RUN: %clang_cc1 -std=c++0x -fsyntax-only -verify %s
+
+template<typename T>
+class unique_ptr {
+  T *ptr;
+
+  unique_ptr(const unique_ptr&) = delete; // expected-note 3{{function has been explicitly marked deleted here}}
+  unique_ptr &operator=(const unique_ptr&) = delete; // expected-note{{candidate function has been explicitly deleted}}
+public:
+  unique_ptr() : ptr(0) { }
+  unique_ptr(unique_ptr &&other) : ptr(other.ptr) { other.ptr = 0; }
+  explicit unique_ptr(T *ptr) : ptr(ptr) { }
+
+  ~unique_ptr() { delete ptr; }
+
+  unique_ptr &operator=(unique_ptr &&other) { // expected-note{{candidate function not viable: no known conversion from 'unique_ptr<int>' to 'unique_ptr<int> &&' for 1st argument}}
+    if (this == &other)
+      return *this;
+
+    delete ptr;
+    ptr = other.ptr;
+    other.ptr = 0;
+    return *this;
+  }
+};
+
+template<typename T>
+struct remove_reference {
+  typedef T type;
+};
+
+template<typename T>
+struct remove_reference<T&> {
+  typedef T type;
+};
+
+template<typename T>
+struct remove_reference<T&&> {
+  typedef T type;
+};
+
+
+template <class T> typename remove_reference<T>::type&& move(T&& t) {
+  return static_cast<typename remove_reference<T>::type&&>(t);
+}
+
+template <class T> T&& forward(typename remove_reference<T>::type& t) {
+  return static_cast<T&&>(t);
+}
+
+template <class T> T&& forward(typename remove_reference<T>::type&& t) {
+  return static_cast<T&&>(t);
+}
+
+template<typename T, typename ...Args>
+unique_ptr<T> make_unique_ptr(Args &&...args) {
+  return unique_ptr<T>(new T(forward<Args>(args)...));
+}
+
+template<typename T> void accept_unique_ptr(unique_ptr<T>); // expected-note{{passing argument to parameter here}}
+
+void test_unique_ptr() {
+  // Simple construction
+  unique_ptr<int> p;
+  unique_ptr<int> p1(new int);
+
+  // Move construction
+  unique_ptr<int> p2(make_unique_ptr<int>(17));
+  unique_ptr<int> p3 = make_unique_ptr<int>(17);
+
+  // Copy construction (failures)
+  unique_ptr<int> p4(p); // expected-error{{call to deleted constructor of 'unique_ptr<int>'}}
+  unique_ptr<int> p5 = p; // expected-error{{call to deleted constructor of 'unique_ptr<int>'}}
+
+  // Move assignment
+  p2 = move(p);
+  p2 = make_unique_ptr<int>(0);
+
+  // Copy assignment (failures);
+  p2 = p3; // expected-error{{overload resolution selected deleted operator '='}}
+
+  // Implicit copies
+  accept_unique_ptr(make_unique_ptr<double>(0.0));
+  accept_unique_ptr(move(p2));
+
+  // Implicit copies (failures);
+  accept_unique_ptr(p); // expected-error{{call to deleted constructor of 'unique_ptr<int>'}}
+}