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 #include "base/callback.h" 6 7 namespace base { 8 9 class Parent { 10 }; 11 12 class Child : Parent { 13 }; 14 15 #if defined(NCTEST_EQUALS_REQUIRES_SAMETYPE) // [r"no matching function for call to 'base::Callback<void\(\)>::Equals\(base::Callback<int\(\)>&\)'"] 16 17 // Attempting to call comparison function on two callbacks of different type. 18 // 19 // This should be a compile time failure because each callback type should be 20 // considered distinct. 21 void WontCompile() { 22 Closure c1; 23 Callback<int(void)> c2; 24 c1.Equals(c2); 25 } 26 27 #elif defined(NCTEST_CONSTRUCTION_FROM_SUBTYPE) // [r"conversion from 'base::Callback<base::Parent\(\)>' to non-scalar type 'base::Callback<base::Child\(\)>'"] 28 29 // Construction of Callback<A> from Callback<B> if A is supertype of B. 30 // 31 // While this is technically safe, most people aren't used to it when coding 32 // C++ so if this is happening, it is almost certainly an error. 33 void WontCompile() { 34 Callback<Parent(void)> cb_a; 35 Callback<Child(void)> cb_b = cb_a; 36 } 37 38 #elif defined(NCTEST_ASSIGNMENT_FROM_SUBTYPE) // [r"no match for 'operator=' in 'cb_a = cb_b'"] 39 40 // Assignment of Callback<A> from Callback<B> if A is supertype of B. 41 // See explanation for NCTEST_CONSTRUCTION_FROM_SUBTYPE 42 void WontCompile() { 43 Callback<Parent(void)> cb_a; 44 Callback<Child(void)> cb_b; 45 cb_a = cb_b; 46 } 47 48 #endif 49 50 } // namespace base 51
