CoCreateGuid

CoCreateGuid is a Windows API function used to generate a new globally unique identifier (GUID) for use in COM programming and related areas. A GUID is a 128-bit value designed to be unique across space and time, making it suitable for identifying COM classes, interfaces, and other entities that require a distinct identifier.

The function commonly fills a GUID structure with a newly generated value and is defined to return an HRESULT to indicate success or failure. A typical usage pattern is to declare a GUID variable, call CoCreateGuid with the address of that variable, and then check the result. If needed, the GUID can be converted to a printable string using a separate routine such as StringFromGUID2 for storage or display.

Signature and data types:

- HRESULT CoCreateGuid(GUID *pguid);

- The GUID type is a 128-bit struct typically represented as Data1, Data2, Data3, and Data4 fields.

Usage considerations:

- CoCreateGuid is commonly used when creating new COM objects, assigning identifiers to interfaces, or generating persistent identifiers for storage or communication.

- The produced value adheres to the standard GUID format, ensuring interoperability across Windows components that rely on GUIDs.

- To obtain a human-readable form, functions like StringFromGUID2 can be used, and the GUID can also be formatted in various textual representations as needed.

Related topics include GUIDs in general, the UUID standard, and alternative Windows or RPC GUID generation functions such as UuidCreate. CoCreateGuid is part of the Windows API ecosystem and is a standard tool for reliably generating unique identifiers in software that runs on Windows.