TWeakPtr

struct Core Since 4.0

#include "Templates/SharedPointer.h"

Description

A non-intrusive weak reference to an object managed by TSharedPtr/TSharedRef. Does not contribute to the reference count and becomes invalid when all strong references are gone.

Signature

template<class ObjectType, ESPMode InMode> class TWeakPtr

Caveats & Gotchas

• TWeakPtr is for non-UObject types only. For UObject weak references use TWeakObjectPtr.
• To use the pointer, call Pin() to get a TSharedPtr — this atomically checks validity and creates a strong reference.
• Not thread-safe by default. Use ESPMode::ThreadSafe if shared across threads.

Example

Observer pattern with TWeakPtr C++

TWeakPtr<FMySystem> WeakSystem;

TSharedPtr<FMySystem> System = MakeShared<FMySystem>();
WeakSystem = System;

// Later, after System may have been released:
if (TSharedPtr<FMySystem> Pinned = WeakSystem.Pin())
{
    Pinned->DoWork();
}

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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