#ifndef _NTRTL_H

/**
 * The RtlGetExtendedContextLength routine computes the length required for an extended context structure.
 *
 * \param ContextFlags Flags that specify which portions of the context are included.
 * \param ContextLength A pointer to a variable that receives the required length, in bytes.
 * \return NTSTATUS Successful or errant status.
 * \remarks Query the required backing size for the actual architecture/context flags before initialization. The initialized CONTEXT_EX describes chunks within the caller allocation; initialization is not capture of current CPU register values. XSTATE feature availability and alignment depend on the target architecture and machine configuration.
 */
NTSYSAPI
NTSTATUS
NTAPI
RtlGetExtendedContextLength(
    _In_ ULONG ContextFlags,
    _Out_ PULONG ContextLength
    );

#endif
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