jcktrue.dk/content/post/bit-magic/index.md

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title: "Bit magic in C (and C++)"
subtitle: ""
summary: ""
authors: []
tags: []
categories: []
date: 2020-06-13T19:01:19+02:00
lastmod: 2020-06-13T19:01:19+02:00
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# Set a bit
```c
// Set one bit high at position "bit" in input and store to output
output = input | (1 << bit);
// Shorthand
variable |= (1 << bit);
// Multiple bits
variable |= (0b101 << bit);
```

# Clear a bit
```c
// Clear one bit high at position "bit" in input and store to output
output = input & ~(1 << bit);
// Shorthand
variable &= ~(1 << bit);
// Multiple bits
variable &= ~(0b101 << bit);

```

# Toggle a bit
```c
// Clear one bit high at position "bit" in input and store to output
output = x ^ (1 << bit);
// Shorthand
variable ^= (1 << bit);
// Multiple bits
variable ^= (0b101 << bit);
```