abool/README.md

# ABool :bulb:

[![Go Report Card](https://goreportcard.com/badge/github.com/tevino/abool)](https://goreportcard.com/report/github.com/tevino/abool)
[![GoDoc](https://godoc.org/github.com/tevino/abool?status.svg)](https://godoc.org/github.com/tevino/abool)

Atomic Boolean package for Go, optimized for performance yet simple to use.

Designed for cleaner code.

## Usage

```go
import "github.com/tevino/abool/v2"

cond := abool.New()     // default to false

cond.Set()              // Sets to true
cond.IsSet()            // Returns true
cond.UnSet()            // Sets to false
cond.IsNotSet()         // Returns true
cond.SetTo(any)         // Sets to whatever you want
cond.SetToIf(old, new)  // Sets to `new` only if the Boolean matches the `old`, returns whether succeeded
cond.Toggle()           // Flip the value of `cond`, returns the value before flipping


// embedding
type Foo struct {
    cond *abool.AtomicBool  // always use pointer to avoid copy
}
```

## Benchmark:

- Go 1.6.2
- OS X 10.11.4
- Intel CPU (to be specified)


```
# Read
BenchmarkMutexRead-4       	100000000	        21.0 ns/op
BenchmarkAtomicValueRead-4 	200000000	         6.30 ns/op
BenchmarkAtomicBoolRead-4  	300000000	         4.21 ns/op  # <--- This package

# Write
BenchmarkMutexWrite-4      	100000000	        21.6 ns/op
BenchmarkAtomicValueWrite-4	 30000000	        43.4 ns/op
BenchmarkAtomicBoolWrite-4 	200000000	         9.87 ns/op  # <--- This package

# CAS
BenchmarkMutexCAS-4        	 30000000	        44.9 ns/op
BenchmarkAtomicBoolCAS-4   	100000000	        11.7 ns/op   # <--- This package
```

## Special thanks to contributors

- [barryz](https://github.com/barryz)
  - Added the `Toggle` method
- [Lucas Rouckhout](https://github.com/LucasRouckhout)
  - Implemented JSON Unmarshal and Marshal interface
- [Sebastian Schicho](https://github.com/schicho)
  - Reported a regression with test case
  - Reintroduced the `Toggle` method