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| 1 // Copyright 2015 The Crashpad Authors. All rights reserved. |
| 2 // |
| 3 // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 // you may not use this file except in compliance with the License. |
| 5 // You may obtain a copy of the License at |
| 6 // |
| 7 // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 // |
| 9 // Unless required by applicable law or agreed to in writing, software |
| 10 // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 // See the License for the specific language governing permissions and |
| 13 // limitations under the License. |
| 14 |
| 15 #ifndef CRASHPAD_UTIL_MISC_IMPLICIT_CAST_H_ |
| 16 #define CRASHPAD_UTIL_MISC_IMPLICIT_CAST_H_ |
| 17 |
| 18 namespace crashpad { |
| 19 |
| 20 // Use implicit_cast as a safe version of static_cast or const_cast |
| 21 // for upcasting in the type hierarchy (i.e. casting a pointer to Foo |
| 22 // to a pointer to SuperclassOfFoo or casting a pointer to Foo to |
| 23 // a const pointer to Foo). |
| 24 // When you use implicit_cast, the compiler checks that the cast is safe. |
| 25 // Such explicit implicit_casts are necessary in surprisingly many |
| 26 // situations where C++ demands an exact type match instead of an |
| 27 // argument type convertible to a target type. |
| 28 // |
| 29 // The From type can be inferred, so the preferred syntax for using |
| 30 // implicit_cast is the same as for static_cast etc.: |
| 31 // |
| 32 // implicit_cast<ToType>(expr) |
| 33 // |
| 34 // implicit_cast would have been part of the C++ standard library, |
| 35 // but the proposal was submitted too late. It will probably make |
| 36 // its way into the language in the future. |
| 37 template<typename To, typename From> |
| 38 inline To implicit_cast(From const &f) { |
| 39 return f; |
| 40 } |
| 41 |
| 42 } // namespace crashpad |
| 43 |
| 44 #endif // CRASHPAD_UTIL_MISC_IMPLICIT_CAST_H_ |
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