xref: /aosp_15_r20/external/libchrome/base/callback_unittest.nc (revision 635a864187cb8b6c713ff48b7e790a6b21769273)
1// Copyright (c) 2011 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// This is a "No Compile Test" suite.
6// http://dev.chromium.org/developers/testing/no-compile-tests
7
8#include "base/callback.h"
9
10namespace base {
11
12class Parent {
13};
14
15class Child : Parent {
16};
17
18#if defined(NCTEST_EQUALS_REQUIRES_SAMETYPE)  // [r"fatal error: no viable conversion from 'RepeatingCallback<int \(\)>' to 'const RepeatingCallback<void \(\)>'"]
19
20// Attempting to call comparison function on two callbacks of different type.
21//
22// This should be a compile time failure because each callback type should be
23// considered distinct.
24void WontCompile() {
25  Closure c1;
26  Callback<int()> c2;
27  c1.Equals(c2);
28}
29
30#elif defined(NCTEST_CONSTRUCTION_FROM_SUBTYPE)  // [r"fatal error: no viable conversion from 'Callback<base::Parent \(\)>' to 'Callback<base::Child \(\)>'"]
31
32// Construction of Callback<A> from Callback<B> if A is supertype of B.
33//
34// While this is technically safe, most people aren't used to it when coding
35// C++ so if this is happening, it is almost certainly an error.
36void WontCompile() {
37  Callback<Parent()> cb_a;
38  Callback<Child()> cb_b = cb_a;
39}
40
41#elif defined(NCTEST_ASSIGNMENT_FROM_SUBTYPE)  // [r"fatal error: no viable overloaded '='"]
42
43// Assignment of Callback<A> from Callback<B> if A is supertype of B.
44// See explanation for NCTEST_CONSTRUCTION_FROM_SUBTYPE
45void WontCompile() {
46  Callback<Parent()> cb_a;
47  Callback<Child()> cb_b;
48  cb_a = cb_b;
49}
50
51#endif
52
53}  // namespace base
54