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> Unreal Engine API Reference > Plugins > ConcertSyncClient > IConcertClientDataStore > IConcertClientDataStore::CompareExchange

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IConcertClientDataStore::CompareExchange

Exchanges the stored value to _Desired_ if a stored value corresponding to _Key_ exists, has the same type and its value is equal to _Expected_, otherwise, the operation fails.

Windows

MacOS

Linux

References

Module	ConcertSyncClient
Header	/Engine/Plugins/Developer/Concert/ConcertSync/ConcertSyncClient/Source/ConcertSyncClient/Public/IConcertClientDataStore.h
Include	#include "IConcertClientDataStore.h"

Syntax

template<typename T>
TFuture< TConcertDataStoreResult< T > > CompareExchange
(
    const FName & Key,
    const T & Expected,
    const T & Desired
)

Remarks

Exchanges the stored value to Desired if a stored value corresponding to Key exists, has the same type and its value is equal to Expected, otherwise, the operation fails.

Returns

Whether or not the key value was exchanged, as a future. The result code can be:

EConcertDataStoreResultCode::Exchanged if the desired value was sucessfully exchanged and stored.
EConcertDataStoreResultCode::Fetched if the stored value was not the expected one. The stored value was fetched instead.
EConcertDataStoreResultCode::NotFound if the key could not be found.
EConcertDataStoreResultCode::TypeMismatch if the stored data type did not match the expected/desired type.

Parameters

Parameter	Description
T	Any USTRUCT() struct or a supported basic types (int8, uint8, int16, uint16, int32, uint32, int64, uint64, float, double, bool, FName, FText, FString).
Key	The value name.
Expected	The value the caller expects to be stored.
Desired	The value the caller wants to store.