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40 lines
1.1 KiB
C++
40 lines
1.1 KiB
C++
#pragma once
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#include <memory>
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namespace ext
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{
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/** Allows to make std::shared_ptr from T with protected constructor.
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*
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* Derive your T class from shared_ptr_helper<T>
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* and you will have static 'create' method in your class.
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*
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* Downsides:
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* - your class cannot be final;
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* - bad compilation error messages;
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* - bad code navigation.
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* - different dynamic type of created object, you cannot use typeid.
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*/
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template <typename T>
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struct shared_ptr_helper
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{
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template <typename... TArgs>
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static auto create(TArgs &&... args)
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{
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/** Local struct makes protected constructor to be accessible by std::make_shared function.
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* This trick is suggested by Yurii Diachenko,
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* inspired by https://habrahabr.ru/company/mailru/blog/341584/
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* that is translation of http://videocortex.io/2017/Bestiary/#-voldemort-types
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*/
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struct Local : T
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{
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Local(TArgs &&... args) : T(std::forward<TArgs>(args)...) {};
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};
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return std::make_shared<Local>(std::forward<TArgs>(args)...);
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}
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};
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}
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