Bit Manipulation

Introduction

A header-only bit manipulation library written in C++20, supporting:

• Getting bits, bytes, words or double words in an integral value.
• Clearing bits, bytes, words or double words in an integral value.
• Setting bits, bytes, words or double words in an integral value.
• Filling bits, bytes, words or double words in an integral value.
• Combining bits, bytes, words or double words to a larger integral value.

Unit Tests

Prerequisites

• Install GoogleTest.
• Install CMake.

Building

Go to the project folder and run:

mkdir -p build
cd build
cmake ..
cmake --build .

Running

Go to the build folder and run:

ctest -VV

Examples

See more examples in tests/bit_manip_tests.cpp.

// Get the specified bits in an integral value.
constexpr std::uint32_t val {0x12345678};
EXPECT_EQ(GetBits(val, 0, sizeof(std::uint8_t) * CHAR_BIT), 0x78);
EXPECT_EQ(GetBits(val, 0, sizeof(std::uint16_t) * CHAR_BIT), 0x5678);

// Set the value of the specified bits in an integral value.
std::uint32_t val {0x12345678};
SetBits(val, 0xFFFF, 0, sizeof(std::uint16_t) * CHAR_BIT);
EXPECT_EQ(val, 0x1234FFFF);

// Fill the specified bits in an integral value.
std::uint32_t val {0x12345678};
FillBits(val, 0, sizeof(std::uint8_t) * CHAR_BIT);
EXPECT_EQ(val, 0x123456FF);

// Clear the specified bits in an integral value.
std::uint32_t val {0x12345678};
ClearBits(val, 0, sizeof(std::uint16_t) * CHAR_BIT);
EXPECT_EQ(val, 0x12340000);

// Combine low bits and high bits into a new integral value.
EXPECT_EQ((CombineBits<std::uint16_t, std::uint8_t>(0x12, 0x34)), 0x1234);
EXPECT_EQ((CombineBits<std::uint32_t, std::uint16_t>(0x1234, 0x5678)), 0x12345678);

// Check if a bit is set in an integral value.
constexpr std::uint8_t val {0b0000'0001};
EXPECT_TRUE(IsBitSet(val, 0));
EXPECT_FALSE(IsBitSet(val, 1));

License

Distributed under the MIT License. See LICENSE for more information.