RtlInitEmptyAnsiString - NtDoc

#ifndef _NTRTL_H

//
// Strings
//

_At_(AnsiString->Buffer, _Post_equal_to_(Buffer))
_At_(AnsiString->Length, _Post_equal_to_(0))
_At_(AnsiString->MaximumLength, _Post_equal_to_(MaximumLength))
FORCEINLINE
VOID
NTAPI_INLINE
RtlInitEmptyAnsiString(
    _Out_ PANSI_STRING AnsiString,
    _Pre_maybenull_ _Pre_readable_size_(MaximumLength) __drv_aliasesMem PCHAR Buffer,
    _In_ USHORT MaximumLength
    )
{
    memset(AnsiString, 0, sizeof(ANSI_STRING));
    AnsiString->MaximumLength = MaximumLength;
    AnsiString->Buffer = Buffer;
}

#endif
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