bitmask provides a type-safe and verbose way to conveniently operate on bit masks.

First, to use this library you need to add it to your go module:

$ go get github.com/kerelape/bitmask

Functions in this module can work with any uint64 derivative, but for convenience there is a predefined type alias called Mask, and it is recommended to use it as the base type for your own masks.

To start working with a new mask, first you should declare it:

import (
    "github.com/kerelape/bitmask"
)

// MyMask is a new fancy mask type.
type MyMask bitmask.Mask

Then declare the flags, that can be set in the mask:

const (
    MyMaskFlag1 bitmask.Flag[MyMask] = 1 << iota
    MyMaskFlag2
    MyMaskFlag3
    ...
    MyMaskFlag64
)

Then, to create and instance of the mask, you can utilize the New[M](...Flag[M]) M function:

mask := bitmask.New[MyMask]()

// or with optional initial flags
mask := bitmask.New[MyMask](MyMaskFlag1, MyMaskFlag2)

The function simply initializes the mask of type M (MyMask in this case), and can be provided with an arbitary amount of initial flags to be set to the mask.

Then you can work with the mask:

hasFlag1 := bitmask.Has(mask, MyMaskFlag1) // true if the flag is set in the mask
mask = bitmask.Set(mask, MyMaskFlag2) // sets the flag to the mask and returns it
mask = bitmask.Clear(mask, MyMaskFlag1) // unsets the flag in the mask and returns it