ceph/src/arrow/cpp/src/arrow/util/checked_cast_test.cc

   1 // Licensed to the Apache Software Foundation (ASF) under one
   2 // or more contributor license agreements.  See the NOTICE file
   3 // distributed with this work for additional information
   4 // regarding copyright ownership.  The ASF licenses this file
   5 // to you under the Apache License, Version 2.0 (the
   6 // "License"); you may not use this file except in compliance
   7 // with the License.  You may obtain a copy of the License at
   8 //
   9 //   http://www.apache.org/licenses/LICENSE-2.0
  10 //
  11 // Unless required by applicable law or agreed to in writing,
  12 // software distributed under the License is distributed on an
  13 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  14 // KIND, either express or implied.  See the License for the
  15 // specific language governing permissions and limitations
  16 // under the License.
  17
  18 #include <type_traits>
  19 #include <typeinfo>
  20
  21 #include <gtest/gtest.h>
  22
  23 #include "arrow/util/checked_cast.h"
  24
  25 namespace arrow {
  26 namespace internal {
  27
  28 class Foo {
  29  public:
  30   virtual ~Foo() = default;
  31 };
  32
  33 class Bar {};
  34 class FooSub : public Foo {};
  35 template <typename T>
  36 class Baz : public Foo {};
  37
  38 TEST(CheckedCast, TestInvalidSubclassCast) {
  39   static_assert(std::is_polymorphic<Foo>::value, "Foo is not polymorphic");
  40
  41   Foo foo;
  42   FooSub foosub;
  43   const Foo& foosubref = foosub;
  44   Baz<double> baz;
  45   const Foo& bazref = baz;
  46
  47 #ifndef NDEBUG  // debug mode
  48   // illegal pointer cast
  49   ASSERT_EQ(nullptr, checked_cast<Bar*>(&foo));
  50
  51   // illegal reference cast
  52   ASSERT_THROW(checked_cast<const Bar&>(foosubref), std::bad_cast);
  53
  54   // legal reference casts
  55   ASSERT_NO_THROW(checked_cast<const FooSub&>(foosubref));
  56   ASSERT_NO_THROW(checked_cast<const Baz<double>&>(bazref));
  57 #else  // release mode
  58   // failure modes for the invalid casts occur at compile time
  59
  60   // legal pointer cast
  61   ASSERT_NE(nullptr, checked_cast<const FooSub*>(&foosubref));
  62
  63   // legal reference casts: this is static_cast in a release build, so ASSERT_NO_THROW
  64   // doesn't make a whole lot of sense here.
  65   auto& x = checked_cast<const FooSub&>(foosubref);
  66   ASSERT_EQ(&foosubref, &x);
  67
  68   auto& y = checked_cast<const Baz<double>&>(bazref);
  69   ASSERT_EQ(&bazref, &y);
  70 #endif
  71 }
  72
  73 }  // namespace internal
  74 }  // namespace arrow