initial code repo

[stor4nfv.git] / src / ceph / src / test / common / test_backport14.cc

diff --git a/src/ceph/src/test/common/test_backport14.cc b/src/ceph/src/test/common/test_backport14.cc
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+++ b/src/ceph/src/test/common/test_backport14.cc
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2017 Red Hat, Inc.
+ *
+ * Author: Casey Bodley <cbodley@redhat.com>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#include "common/backport14.h" // include first: tests that header is standalone
+#include <gtest/gtest.h>
+
+int int_func() { return 1; }
+bool bool_func0() { return true; }
+bool bool_func1(int a) { return true; }
+bool bool_func2(const std::string& a, int b) { return true; }
+
+// given a callable and argument list, test that the result of ceph::not_fn
+// evaluates to false as both an lvalue and rvalue
+template <typename F, typename ...Args>
+void test_not(F&& fn, Args&&... args)
+{
+  auto res = ceph::not_fn(std::forward<F>(fn));
+  // test res as lvalue
+  EXPECT_FALSE(res(std::forward<Args>(args)...));
+  // test res as rvalue
+  // note: this forwards args twice, but it's okay if none are rvalues
+  EXPECT_FALSE(std::move(res)(std::forward<Args>(args)...));
+}
+
+TEST(Backport14, not_fn)
+{
+  // function pointers
+  test_not(int_func);
+  test_not(&int_func);
+  test_not(bool_func0);
+  test_not(&bool_func0);
+  test_not(bool_func1, 5);
+  test_not(bool_func2, "foo", 5);
+
+  // lambdas
+  auto int_lambda = [] { return 1; };
+  auto bool_lambda0 = [] { return true; };
+  auto bool_lambda1 = [] (int a) { return true; };
+  auto bool_lambda2 = [] (const std::string& a, int b) { return true; };
+
+  test_not(int_lambda);
+  test_not(bool_lambda0);
+  test_not(bool_lambda1, 5);
+  test_not(bool_lambda2, "foo", 5);
+
+  // functors
+  struct int_functor {
+    int operator()() { return 1; }
+  };
+  test_not(int_functor{});
+
+  struct bool_functor {
+    bool operator()() { return true; }
+    bool operator()(int a) { return true; }
+    bool operator()(const std::string& a, int b) { return true; }
+  };
+
+  test_not(bool_functor{});
+  test_not(bool_functor{}, 5);
+  test_not(bool_functor{}, "foo", 5);
+
+  // lvalue-only overload
+  struct lvalue_only_functor {
+    bool operator()() & { return true; } // no overload for rvalue
+  };
+  auto lvalue_result = ceph::not_fn(lvalue_only_functor{});
+  EXPECT_FALSE(lvalue_result());
+  // should not compile:
+  //   EXPECT_FALSE(std::move(lvalue_result)());
+
+  // rvalue-only overload
+  struct rvalue_only_functor {
+    bool operator()() && { return true; } // no overload for lvalue
+  };
+  EXPECT_FALSE(ceph::not_fn(rvalue_only_functor{})());
+  auto lvalue_functor = rvalue_only_functor{};
+  EXPECT_FALSE(ceph::not_fn(lvalue_functor)()); // lvalue functor, rvalue result
+  // should not compile:
+  //   auto lvalue_result2 = ceph::not_fn(rvalue_only_functor{});
+  //   EXPECT_FALSE(lvalue_result2());
+}