base/template_util_unittest.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/template_util.h"
   6
   7 #include "base/basictypes.h"
   8 #include "testing/gtest/include/gtest/gtest.h"
   9
  10 namespace base {
  11 namespace {
  12
  13 struct AStruct {};
  14 class AClass {};
  15 enum AnEnum {};
  16
  17 class Parent {};
  18 class Child : public Parent {};
  19
  20 // is_pointer<Type>
  21 COMPILE_ASSERT(!is_pointer<int>::value, IsPointer);
  22 COMPILE_ASSERT(!is_pointer<int&>::value, IsPointer);
  23 COMPILE_ASSERT(is_pointer<int*>::value, IsPointer);
  24 COMPILE_ASSERT(is_pointer<const int*>::value, IsPointer);
  25
  26 // is_array<Type>
  27 COMPILE_ASSERT(!is_array<int>::value, IsArray);
  28 COMPILE_ASSERT(!is_array<int*>::value, IsArray);
  29 COMPILE_ASSERT(!is_array<int(*)[3]>::value, IsArray);
  30 COMPILE_ASSERT(is_array<int[]>::value, IsArray);
  31 COMPILE_ASSERT(is_array<const int[]>::value, IsArray);
  32 COMPILE_ASSERT(is_array<int[3]>::value, IsArray);
  33
  34 // is_non_const_reference<Type>
  35 COMPILE_ASSERT(!is_non_const_reference<int>::value, IsNonConstReference);
  36 COMPILE_ASSERT(!is_non_const_reference<const int&>::value, IsNonConstReference);
  37 COMPILE_ASSERT(is_non_const_reference<int&>::value, IsNonConstReference);
  38
  39 // is_convertible<From, To>
  40
  41 // Extra parens needed to make preprocessor macro parsing happy. Otherwise,
  42 // it sees the equivalent of:
  43 //
  44 //     (is_convertible < Child), (Parent > ::value)
  45 //
  46 // Silly C++.
  47 COMPILE_ASSERT( (is_convertible<Child, Parent>::value), IsConvertible);
  48 COMPILE_ASSERT(!(is_convertible<Parent, Child>::value), IsConvertible);
  49 COMPILE_ASSERT(!(is_convertible<Parent, AStruct>::value), IsConvertible);
  50 COMPILE_ASSERT( (is_convertible<int, double>::value), IsConvertible);
  51 COMPILE_ASSERT( (is_convertible<int*, void*>::value), IsConvertible);
  52 COMPILE_ASSERT(!(is_convertible<void*, int*>::value), IsConvertible);
  53
  54 // Array types are an easy corner case.  Make sure to test that
  55 // it does indeed compile.
  56 COMPILE_ASSERT(!(is_convertible<int[10], double>::value), IsConvertible);
  57 COMPILE_ASSERT(!(is_convertible<double, int[10]>::value), IsConvertible);
  58 COMPILE_ASSERT( (is_convertible<int[10], int*>::value), IsConvertible);
  59
  60 // is_same<Type1, Type2>
  61 COMPILE_ASSERT(!(is_same<Child, Parent>::value), IsSame);
  62 COMPILE_ASSERT(!(is_same<Parent, Child>::value), IsSame);
  63 COMPILE_ASSERT( (is_same<Parent, Parent>::value), IsSame);
  64 COMPILE_ASSERT( (is_same<int*, int*>::value), IsSame);
  65 COMPILE_ASSERT( (is_same<int, int>::value), IsSame);
  66 COMPILE_ASSERT( (is_same<void, void>::value), IsSame);
  67 COMPILE_ASSERT(!(is_same<int, double>::value), IsSame);
  68
  69
  70 // is_class<Type>
  71 COMPILE_ASSERT(is_class<AStruct>::value, IsClass);
  72 COMPILE_ASSERT(is_class<AClass>::value, IsClass);
  73 COMPILE_ASSERT(!is_class<AnEnum>::value, IsClass);
  74 COMPILE_ASSERT(!is_class<int>::value, IsClass);
  75 COMPILE_ASSERT(!is_class<char*>::value, IsClass);
  76 COMPILE_ASSERT(!is_class<int&>::value, IsClass);
  77 COMPILE_ASSERT(!is_class<char[3]>::value, IsClass);
  78
  79 }  // namespace
  80 }  // namespace base