vba-bitwise

Bitwise Pperations Class using LongPtr (x86 and x64)

A predeclared Bitwise Operations Class for VBA with:

• Full set of bitwise operations on LongPtr (32-bit on x86, 64-bit on x64)
• Byte-level lookup tables for fast Count, Reverse, and BitString
• Shift, rotate, flip, swap, clear, and random operations
• Zero dependencies (pure VBA)

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📦 Features

• Predeclared — accessible as Bitwise.Method(...) without instantiation
• x86 / x64 — uses LongPtr throughout; all operations work on 32 or 64 bits
• Lookup tables — Count, Reverse, and BitString use precalculated byte tables (3–4× faster than bit-by-bit)
• Optional StringTable — set #Const UseStringTable = True to trade ~5 KB memory for faster BitString
• Pure VBA, no external references, Rubberduck-friendly annotations

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⚙️ Public Interface

Methods

Member	Returns	Description
Count(bits)	Long	Number of set bits in the pattern.
Flip(bits, No)	LongPtr	Flips bit No.
Swap(bits, No1, No2)	LongPtr	Swaps bits No1 and No2.
Inverse(bits)	LongPtr	Inverts all bits (Not bits).
Reverse(bits)	LongPtr	Reverses the bit order.
Clear(bits, No)	LongPtr	Clears bit No.
LClear(bits, No)	LongPtr	Clears all bits to the left of bit No.
RClear(bits, No)	LongPtr	Clears all bits to the right of bit No.
LShift(bits, amount)	LongPtr	Logical left shift by amount.
RShift(bits, amount)	LongPtr	Logical right shift by amount (fills with 0).
Shift(bits, amount)	LongPtr	Left if amount < 0, right if amount > 0.
Rotate(bits, amount)	LongPtr	Left if amount < 0, right if amount > 0.
Random()	LongPtr	Pseudo-random bit pattern.

Properties

Member	Type	Description
Bit(bits, No) (Default)	Boolean	Gets or sets bit No in bits (passed ByRef).
BitArray(bits)	Boolean()	Converts between a bit pattern and a Boolean array.
BitString(bits)	String	Converts between a bit pattern and a "0"/"1" string.

Error behavior

• BitArray raises vbErrorInvalidProcedureCall (5) for empty, zero-length, or oversized arrays.
• BitString raises vbErrorInvalidProcedureCall (5) for empty, oversized, or non-binary strings.

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🚀 Quick Start

Dim bits As LongPtr

' Set and read individual bits
Bitwise.Bit(bits, 3) = True
Debug.Print Bitwise.Bit(bits, 3)    ' -> True
Debug.Print Bitwise.BitString(bits) ' -> "...00001000"

' Shift and rotate
bits = Bitwise.LShift(bits, 2)      ' bit 3 -> bit 5
bits = Bitwise.Rotate(bits, 1)      ' rotate right by 1

' Count set bits
Debug.Print Bitwise.Count(bits)     ' -> 1

' Convert to/from string
Bitwise.BitString(bits) = "00001111"
Debug.Print Bitwise.Count(bits)     ' -> 4

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⏱️ Performance

Timings (ms) per operation, measured on Windows x64:

Method	Time (ms)	Notes
Count	0.00022	Byte lookup table
Flip	0.00007
Inverse	0.00007
Swap	0.00010
Shift	0.00011
Rotate	0.00014
Random	0.00022
Reverse	0.00033	Byte lookup table
BitString	0.00034	Byte lookup table

A standard module implementation is typically 10–20% faster than the class.

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🧠 Memory Usage

Table / Mask	Size (x64)
BitMask()	544 bytes
MaxMask()	544 bytes
ReverseTable()	288 bytes
CountTable()	288 bytes
StringTable()	5,664 bytes (optional, #Const UseStringTable = True)

Total without StringTable: ~1.7 KB. With: ~7.3 KB.

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📄 License

MIT © 2025 Vincent van Geerestein