TArray::AllocatorInstance

property Core Since 4.0

#include "Containers/Array.h"

Access: protected

Description

The allocator object responsible for managing the raw memory backing the array. Its type is the second template parameter of TArray (defaulting to FDefaultAllocator).

Caveats & Gotchas

• Accessing AllocatorInstance directly bypasses all of TArray's element lifetime management (construction, destruction, move semantics). Writing to the raw allocation without going through TArray APIs will silently produce memory corruption.
• For inline allocators (e.g. TInlineAllocator<N>), AllocatorInstance contains the stack buffer itself, not a pointer to it. This means copying a TArray with an inline allocator copies the entire stack buffer — be mindful of stack pressure for large inline sizes.

Signature

ElementAllocatorType AllocatorInstance

Example

Custom allocator TArray declaration C++

// Use a stack-inline allocator for up to 8 elements before heap overflow:
TArray<FVector, TInlineAllocator<8>> SmallPath;
// AllocatorInstance here is a TInlineAllocator<8> holding 8 FVectors on the stack.
SmallPath.Add(FVector::ZeroVector); // no heap alloc

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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