Bitwise operations in C++ Bitset

24 Sep 2023

cplusplus

Bitwise operations are fundamental operations in computer programming that manipulate individual bits within binary numbers. These operations are commonly used in scenarios where we need to perform low-level optimizations or work with binary data. In this article, we will explore bitwise operations using the C++ bitset class.

The bitset is a powerful class in C++ that provides a high-level interface to manipulate and operate on a fixed number of bits. It encapsulates an array of bits and provides various member functions to perform bitwise operations.

Creating a `bitset`

To start using the bitset class, you first need to include the <bitset> header. Then, you can create a bitset object by specifying the number of bits it should store.

#include <bitset>

constexpr int BITS_COUNT = 8;
std::bitset<BITS_COUNT> bits;

In the above example, we create a bitset object called bits with 8 bits. This will create a bitset that can hold 8 binary digits.

Setting and Accessing Bits

Once you have a bitset, you can set and access individual bits using the [] operator.

bits[0] = 1; // Set the first bit to 1
bits[3] = 0; // Set the fourth bit to 0

bool firstBit = bits[0]; // Access the first bit

In the above code snippet, we set the first bit of bits to 1 and the fourth bit to 0. We also access the value of the first bit and store it in the firstBit variable.

Bitwise Operations

The bitset class provides a set of member functions to perform bitwise operations.

AND Operation

To perform the logical AND operation between two bitset objects, we can use the & operator or the and member function.

std::bitset<BITS_COUNT> bits1("01010101");
std::bitset<BITS_COUNT> bits2("00110011");
std::bitset<BITS_COUNT> result = bits1 & bits2;

In the above code, we perform the AND operation between bits1 and bits2 and store the result in the result bitset object.

OR Operation

To perform the logical OR operation between two bitset objects, we can use the | operator or the or member function.

std::bitset<BITS_COUNT> bits1("01010101");
std::bitset<BITS_COUNT> bits2("00110011");
std::bitset<BITS_COUNT> result = bits1 | bits2;

In the above code, we perform the OR operation between bits1 and bits2 and store the result in the result bitset object.

XOR Operation

To perform the logical XOR operation between two bitset objects, we can use the ^ operator or the xor member function.

std::bitset<BITS_COUNT> bits1("01010101");
std::bitset<BITS_COUNT> bits2("00110011");
std::bitset<BITS_COUNT> result = bits1 ^ bits2;

In the above code, we perform the XOR operation between bits1 and bits2 and store the result in the result bitset object.

Conclusion

Bitwise operations with the C++ bitset class provide a convenient way to manipulate bits at a low level. Whether you need to perform logical operations or bitwise manipulations, the bitset class offers an efficient and easy-to-use interface.

Understanding bitwise operations is crucial in optimizing algorithms, working with binary data, and implementing various data structures. By leveraging the power of bitset, you can simplify your code and take advantage of the low-level bit manipulation capabilities provided by the C++ language.

#cplusplus #bitwiseoperations

Creating a bitset