Improving flat containers interface.

base/functional_unittest.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/functional.h"
+
+#include <memory>
+#include <string>
+
+#include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/strings/string_piece.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+namespace {
+
+class Smart : public RefCounted<Smart> {
+  Smart() = default;
+  Smart(const Smart&) = default;
+  Smart& operator=(const Smart&) = default;
+
+  WeakPtr<Smart> GetWeakPtr() { return weak_factory_.GetWeakPtr(); }
+
+ private:
+  friend class RefCounted<Smart>;
+  ~Smart() = default;
+
+  WeakPtrFactory<Smart> weak_factory_{this};
+};
+
+TEST(Concepts, SmartPointerConcept) {
+  static_assert(SmartPointer<std::unique_ptr<int>>(), "");
+  static_assert(SmartPointer<scoped_refptr<Smart>>, "");
+  static_assert(SmartPointer<WeakPtr<Smart>>, "");
+
+  static_assert(!SmartPointer<int>(), "");
+  static_assert(!SmartPointer<int*>(), "");
+}
+
+TEST(Concepts, ComparableConcept) {
+  static_assert(Comparable<int, int>(), "");
+  static_assert(Comparable<int, double>(), "");
+  static_assert(Comparable<std::unique_ptr<int>, std::unique_ptr<int>>(), "");
+  static_assert(Comparable<std::string, base::StringPiece>(), "");
+  static_assert(!Comparable<int*, std::unique_ptr<int>>(), "");
+}
+
+TEST(Functional, Less) {
+  auto x = base::MakeUnique<int>();
+  EXPECT_FALSE(base::less{}(x, x));
+  EXPECT_TRUE(base::less{}(x, x.get() + 1));
+  EXPECT_FALSE(base::less{}(x.get() + 1, x.get()));
+}
+
+}  // namespace
+
+}  // namespace base