bitArray.H File Reference

Space-efficient bit array implementation. More...

#include <bit>
#include <cstdint>
#include <iostream>
#include <fstream>
#include <algorithm>
#include <type_traits>
#include <aleph.H>
#include <tpl_dynArray.H>
#include <ah-errors.H>
#include <ahDry.H>
#include <ah-dry-mixin.H>

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Classes
class	Aleph::Byte
class	Aleph::BitArray
	Contiguous array of bits. More...
class	Aleph::BitArray::BitProxy
class	Aleph::BitArray::Iterator

Namespaces
namespace	Aleph
	Main namespace for Aleph-w library functions.

Detailed Description

Space-efficient bit array implementation.

This file provides a compact bit array that stores boolean values using only 1 bit per element, achieving 8x memory savings compared to using bool arrays.

Classes Provided

• Byte: Low-level byte manipulation utilities
• BitArray: Dynamic bit array with automatic resizing
• BitProxy: Proxy class for bit-level assignment via operator[]

Key Features

• Memory-efficient: 1 bit per boolean value
• Dynamic resizing with configurable block size
• Bitwise operations (AND, OR, XOR, NOT)
• File I/O support (save/load)
• STL-compatible iteration
• Functional methods via CRTP mixin

Complexity

Operation	Time	Space
read_bit	O(1)	O(1)
write_bit	O(1)	O(1)
resize	O(n)	O(n/8)
AND/OR/XOR	O(n)	O(1)
popcount	O(n)	O(1)

Memory Layout

Bits are packed into bytes, with bit 0 of element i stored in the lowest bit of byte i/8, position i%8.

Usage Example

BitArray bits(100);  // 100 bits, all initialized to 0
 
bits[0] = 1;         // Set bit 0
bits[50] = true;     // Set bit 50
 
if (bits[0])         // Check bit 0
  std::cout << "Bit 0 is set\n";
 
// Bitwise operations
BitArray other(100);
BitArray result = bits & other;  // AND
result = bits | other;           // OR
result = ~bits;                  // NOT
 
// Count set bits
size_t count = bits.popcount();

See also

bloom-filter.H Uses BitArray for Bloom filter implementation

tpl_dynArray.H Underlying storage mechanism

Author

Leandro Rabindranath León

Definition in file bitArray.H.