TArray::CountBytes
#include "Containers/Array.h"
Access: public
Specifiers: const
Description
Reports the array's current and peak memory usage to an accounting archive by calling Ar.CountBytes with the used and allocated byte counts. Used by the engine's memory profiling infrastructure.
Caveats & Gotchas
- • CountBytes reports sizeof(ElementType) * ArrayNum as used and sizeof(ElementType) * ArrayMax as allocated — it does not account for heap allocations made by the elements themselves (e.g. FString members inside a TArray<FString>).
- • This function is only meaningful when called with an FArchive that implements CountBytes accounting (such as FArchiveCountMem). Calling it with a serialization archive is a no-op or undefined behaviour.
Signature
UE_NODEBUG void CountBytes(FArchive& Ar) constParameters
| Name | Type | Description | Default |
|---|---|---|---|
| Ar | FArchive& | Archive used for memory accounting; must support CountBytes() (e.g. FArchiveCountMem). | — |
Return Type
void Example
Measuring array memory usage C++
TArray<FVector> Positions;
Positions.Reserve(1000);
FArchiveCountMem MemAr(nullptr);
Positions.CountBytes(MemAr);
UE_LOG(LogTemp, Log, TEXT("Used: %llu bytes, Reserved: %llu bytes"),
MemAr.GetNum(), MemAr.GetMax());See Also
Version History
Introduced in: 4.0
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
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