[#BloombergLP-bdlb-BitMaskUtil-zero64] = xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdlb.adoc[bdlb]::xref:BloombergLP/bdlb/BitMaskUtil.adoc[BitMaskUtil]::zero64 :relfileprefix: ../../../ :mrdocs: Return the unsigned integral value having the specified `numBits` starting at the specified `index` set to 0, and all other bits set to 1. The behavior is undefined unless `0 <= index`, `0 <= numBits`, and `index + numBits <= # of bits in result`. == Synopsis Declared in `<bdlb_bitmaskutil.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- static uint64_t zero64( int index, int numBits); ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#