// Copyright 2015 The Crashpad Authors // // 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) { … } } // namespace crashpad #endif // CRASHPAD_UTIL_MISC_IMPLICIT_CAST_H_