| // Copyright 2015 The Crashpad Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef CRASHPAD_UTIL_MISC_IMPLICIT_CAST_H_ |
| #define CRASHPAD_UTIL_MISC_IMPLICIT_CAST_H_ |
| |
| namespace crashpad { |
| |
| // Use implicit_cast as a safe version of static_cast or const_cast |
| // for upcasting in the type hierarchy (i.e. casting a pointer to Foo |
| // to a pointer to SuperclassOfFoo or casting a pointer to Foo to |
| // a const pointer to Foo). |
| // When you use implicit_cast, the compiler checks that the cast is safe. |
| // Such explicit implicit_casts are necessary in surprisingly many |
| // situations where C++ demands an exact type match instead of an |
| // argument type convertible to a target type. |
| // |
| // The From type can be inferred, so the preferred syntax for using |
| // implicit_cast is the same as for static_cast etc.: |
| // |
| // implicit_cast<ToType>(expr) |
| // |
| // implicit_cast would have been part of the C++ standard library, |
| // but the proposal was submitted too late. It will probably make |
| // its way into the language in the future. |
| template <typename To, typename From> |
| constexpr To implicit_cast(From const& f) { |
| return f; |
| } |
| |
| } // namespace crashpad |
| |
| #endif // CRASHPAD_UTIL_MISC_IMPLICIT_CAST_H_ |
