1 files changed, 103 insertions, 0 deletions
diff --git a/tests/notnull_tests.cpp b/tests/notnull_tests.cpp
new file mode 100644
index 0000000..526b074
--- /dev/null
+++ b/tests/notnull_tests.cpp
@@ -0,0 +1,103 @@
+/////////////////////////////////////////////////////////////////////////////// 
+// 
+// Copyright (c) 2015 Microsoft Corporation. All rights reserved. 
+// 
+// This code is licensed under the MIT License (MIT). 
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
+// THE SOFTWARE. 
+// 
+///////////////////////////////////////////////////////////////////////////////
+
+#include <UnitTest++/UnitTest++.h> 
+#include <gsl/gsl>
+#include <vector>
+
+using namespace gsl;
+
+struct MyBase {};
+struct MyDerived : public MyBase {};
+struct Unrelated {};
+
+// stand-in for a user-defined ref-counted class
+template<typename T>
+struct RefCounted
+{
+    RefCounted(T* p) : p_(p) {}
+    operator T*() { return p_; }
+    T* p_;
+};
+
+SUITE(NotNullTests)
+{
+
+    bool helper(not_null<int*> p)
+    {
+        return *p == 12;
+    }
+
+    TEST(TestNotNullConstructors)
+    {
+#ifdef CONFIRM_COMPILATION_ERRORS
+        not_null<int*> p = nullptr; // yay...does not compile!
+        not_null<std::vector<char>*> p = 0; // yay...does not compile!
+        not_null<int*> p; // yay...does not compile!
+        std::unique_ptr<int> up = std::make_unique<int>(120);
+        not_null<int*> p = up;
+
+        // Forbid non-nullptr assignable types
+        not_null<std::vector<int>> f(std::vector<int>{1});
+        not_null<int> z(10);
+        not_null<std::vector<int>> y({1,2});
+#endif
+      int i = 12; 
+      auto rp = RefCounted<int>(&i);
+      not_null<int*> p(rp);
+      CHECK(p.get() == &i);
+
+      not_null<std::shared_ptr<int>> x(std::make_shared<int>(10)); // shared_ptr<int> is nullptr assignable
+    }
+
+    TEST(TestNotNullCasting)
+    {
+        MyBase base;
+	MyDerived derived;
+	Unrelated unrelated;
+	not_null<Unrelated*> u = &unrelated;
+        (void)u;
+	not_null<MyDerived*> p = &derived;
+        not_null<MyBase*> q = &base;
+	q = p; // allowed with heterogeneous copy ctor
+        CHECK(q == p);
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+	q = u; // no viable conversion possible between MyBase* and Unrelated*
+	p = q; // not possible to implicitly convert MyBase* to MyDerived*
+
+        not_null<Unrelated*> r = p;
+        not_null<Unrelated*> s = reinterpret_cast<Unrelated*>(p);
+#endif
+        not_null<Unrelated*> t = reinterpret_cast<Unrelated*>(p.get());
+        CHECK((void*)p.get() == (void*)t.get());
+    }
+
+    TEST(TestNotNullAssignment)
+    {
+        int i = 12;
+        not_null<int*> p = &i; 
+        CHECK(helper(p));
+
+        int* q = nullptr;
+        CHECK_THROW(p = q, fail_fast);
+    }
+}
+
+int main(int, const char *[])
+{
+    return UnitTest::RunAllTests();
+}