[#BloombergLP-bdlb-BitMaskUtil]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdlb.adoc[bdlb]::BitMaskUtil
:relfileprefix: ../../
:mrdocs:

Namespace for functions that produce 32‐ and 64‐bit bit masks.

== Synopsis

Declared in `<bdlb_bitmaskutil.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
struct BitMaskUtil;
----

== Description

This utility `struct` provides a namespace for a set of bit‐level, stateless functions that take one or two `int` arguments and return masks of the built‐in 32‐ and 64‐bit integer types `uint32_t` and `uint64_t`, respectively.

== Enums

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bdlb/BitMaskUtil/_04enum.adoc[`Unnamed enum`] 
| Number of bits in type `uint32_t`.
|===


== Static Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bdlb/BitMaskUtil/eq.adoc[`eq`] 
| Return a mask with only the bit at `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/eq64.adoc[`eq64`] 
| Return a mask with only the bit at `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/ge.adoc[`ge`] 
| Return a mask with all bits at or above `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/ge64.adoc[`ge64`] 
| Return a mask with all bits at or above `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/gt.adoc[`gt`] 
| Return a mask with all bits above `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/gt64.adoc[`gt64`] 
| Return a mask with all bits above `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/le.adoc[`le`] 
| Return a mask with all bits at or below `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/le64.adoc[`le64`] 
| Return a mask with all bits at or below `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/lt.adoc[`lt`] 
| Return the unsigned integral value having all bits at positions less than the specified `index` set to 1, and all other bits set to 0.
| xref:BloombergLP/bdlb/BitMaskUtil/lt64.adoc[`lt64`] 
| Return a mask with all bits below `index` set.
| xref:BloombergLP/bdlb/BitMaskUtil/ne.adoc[`ne`] 
| Return a bitmask with the bit at `index` cleared.
| xref:BloombergLP/bdlb/BitMaskUtil/ne64.adoc[`ne64`] 
| Return a bitmask with the bit at `index` cleared.
| xref:BloombergLP/bdlb/BitMaskUtil/one.adoc[`one`] 
| Return a mask with `numBits` bits set starting at `index`.
| xref:BloombergLP/bdlb/BitMaskUtil/one64.adoc[`one64`] 
| Return a mask with `numBits` bits set starting at `index`.
| xref:BloombergLP/bdlb/BitMaskUtil/zero.adoc[`zero`] 
| Return the unsigned integral value having the specified `numBits` starting at the specified `index` set to 0, and all other bits set to 1.
| xref:BloombergLP/bdlb/BitMaskUtil/zero64.adoc[`zero64`] 
| Return a mask with `numBits` bits cleared starting at `index`.
|===



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