#ifndef _NTRTL_H

/**
 * The RtlDestroyHeap routine destroys the specified heap object. RtlDestroyHeap decommits and releases all the pages of a private heap object,
 * and it invalidates the handle to the heap.
 *
 * \param HeapHandle Handle for the heap to be destroyed. This parameter is a heap handle returned by RtlCreateHeap.
 * \return If the call to RtlDestroyHeap succeeds, the return value is a NULL pointer. If the call to RtlDestroyHeap fails, the return value is a handle for the heap.
 * \remarks https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/ntifs/nf-ntifs-rtldestroyheap
 * \remarks Own private heaps created for the component; do not destroy the process default heap. DestroyHeap returns NULL on successful destruction and can return the original handle on failure. All allocations and references from a destroyed heap become invalid; use the correct heap for every block operation.
 */
_Success_(return == 0)
NTSYSAPI
PVOID
NTAPI
RtlDestroyHeap(
    _In_ _Post_invalid_ HANDLE HeapHandle
    );

#endif
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// ntifs.h

NTSYSAPI PVOID RtlDestroyHeap(
  [in] PVOID HeapHandle
);
View the official Windows Driver Kit DDI reference