Add skeleton circular queue file.

base/test/copy_only_int.h

+// 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.
+
+#ifndef BASE_TEST_COPY_ONLY_INT_H_
+#define BASE_TEST_COPY_ONLY_INT_H_
+
+#include "base/macros.h"
+
+namespace base {
+
+// A copy-only (not moveable) class that holds an integer. This is designed for
+// testing containers. See also MoveOnlyInt.
+class CopyOnlyInt {
+ public:
+  explicit CopyOnlyInt(int data = 1) : data_(data) {}
+  CopyOnlyInt(const CopyOnlyInt& other) : data_(other.data_) {}
+  ~CopyOnlyInt() { data_ = 0; }
+
+  friend bool operator==(const CopyOnlyInt& lhs, const CopyOnlyInt& rhs) {
+    return lhs.data_ == rhs.data_;
+  }
+
+  friend bool operator!=(const CopyOnlyInt& lhs, const CopyOnlyInt& rhs) {
+    return !operator==(lhs, rhs);
+  }
+
+  friend bool operator<(const CopyOnlyInt& lhs, const CopyOnlyInt& rhs) {
+    return lhs.data_ < rhs.data_;
+  }
+
+  friend bool operator>(const CopyOnlyInt& lhs, const CopyOnlyInt& rhs) {
+    return rhs < lhs;
+  }
+
+  friend bool operator<=(const CopyOnlyInt& lhs, const CopyOnlyInt& rhs) {
+    return !(rhs < lhs);
+  }
+
+  friend bool operator>=(const CopyOnlyInt& lhs, const CopyOnlyInt& rhs) {
+    return !(lhs < rhs);
+  }
+
+  int data() const { return data_; }
+
+ private:
+  int data_;
+
+  CopyOnlyInt(CopyOnlyInt&&) = delete;
+  CopyOnlyInt& operator=(CopyOnlyInt&) = delete;
+};
+
+}  // namespace base
+
+#endif  // BASE_TEST_COPY_ONLY_INT_H_