46 lines
1.3 KiB
C++
46 lines
1.3 KiB
C++
// Copyright (c) 2004-present, Facebook, Inc.
|
|
|
|
// This source code is licensed under the MIT license found in the
|
|
// LICENSE file in the root directory of this source tree.
|
|
|
|
#pragma once
|
|
|
|
#include <cassert>
|
|
#include <cstdlib>
|
|
#include <type_traits>
|
|
|
|
#ifndef RN_EXPORT
|
|
#define RN_EXPORT __attribute__((visibility("default")))
|
|
#endif
|
|
|
|
namespace facebook {
|
|
namespace react {
|
|
|
|
// Base class for private data used to implement hybrid JS-native objects. A common root class,
|
|
// rtti and dynamic_cast allow us to do some runtime type checking that makes it possible
|
|
// for multiple hybrid object implementations to co-exist.
|
|
class RN_EXPORT PrivateDataBase {
|
|
public:
|
|
virtual ~PrivateDataBase();
|
|
|
|
// Casts given void* to PrivateDataBase and performs dynamic_cast to desired type. Returns null on
|
|
// failure.
|
|
template <typename T>
|
|
static typename std::enable_if<std::is_base_of<PrivateDataBase, T>::value, T>::type* tryCast(void* ptr) {
|
|
return dynamic_cast<T*>(reinterpret_cast<PrivateDataBase*>(ptr));
|
|
}
|
|
|
|
// Like tryCast, but aborts on failure.
|
|
template <typename T>
|
|
static typename std::enable_if<std::is_base_of<PrivateDataBase, T>::value, T>::type* cast(void* ptr) {
|
|
auto result = tryCast<T>(ptr);
|
|
if (!result) {
|
|
assert(false && "could not cast to desired type");
|
|
abort();
|
|
}
|
|
return result;
|
|
}
|
|
};
|
|
|
|
} }
|