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