ScopeObject.h

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/** @noop License Comment
 *  @file
 *  @copyright
 *  This Source Code is subject to the terms of the Mozilla Public License, v2.0.
 *  If a copy of the MPL was not distributed with this file You can obtain one at
 *  https://mozilla.org/MPL/2.0/
 *  
 *  @author David Mórász
 *  @date 2025
*/
 
#pragma once
 
#include "CoreMinimal.h"
#include "UObject/StrongObjectPtr.h"
#include "Mcro/UObjects/Init.h"
 
namespace Mcro::UObjects::Init
{
    /**
     *  @brief
     *  A struct to emulate regular C++ RAII object behavior with UObjects. When this struct is instantiated the given
     *  object type is also created. An object wrapped in this struct is never invalid, and doesn't get garbage
     *  collected until it's in scope.
     *
     *  It is safe to create this struct on any thread, GC is deferred until constructor is finished. The underlying
     *  storage is a `TStrongObjectPtr`.
     *
     *  If the given object type happen to have an `Intialize` member method, that's also called with the extra
     *  arguments provided in the constructor.
     */
    template <CUObject T>
    struct TScopeObject
    {
        template <typename... Args>
        TScopeObject(FConstructObjectParameters&& params, Args&&... args)
        {
            FGCScopeGuard avoidGC;
            Storage.Reset(NewInit<T>(FWD(params), FWD(args)...));
        }
 
        const T* operator -> () const { return Storage.Get(); }
              T* operator -> ()       { return Storage.Get(); }
 
        operator const T* () const { return Storage.Get(); }
        operator       T* ()       { return Storage.Get(); }
 
        T const& Get() const { return *Storage.Get(); }
        T&       Get()       { return *Storage.Get(); }
        
    private:
        TStrongObjectPtr<T> Storage;
    };
}