safecast

Safe Numeric Type Cast Library for Go

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License Apache 2.0 Python Build Status Coverage Status GoReport

Safe numeric type cast library. suppoer all integral and floating types, except uintptr.

This library depends on go generics, which is introduced in 1.18+.

Usage:

val, ok := To[type](value)

ok == false indicates overflow occured. but whatever，val is always equals to the result of the type cast (type(value)) expression。

safecast

import "github.com/chen3feng/safecast"

Package safecast provide a safe way to cast a numeric value from type A to type B, with overflow and underflow check.

Index

func To

func To[ToType numericType, FromType numericType](value FromType) (result ToType, ok bool)

To converts a numeric value from the FromType to the specified ToType type safely. result will always be same as the usual type cast (type(value)), but ok is false when overflow or underflow occured.

Example (Float Overflow) 

package main

import (
	"fmt"
	"github.com/chen3feng/safecast"
	"math"
)

func main() {
	n, ok := safecast.To[float32](math.MaxFloat32 * 2)
	fmt.Print(n, ok)
}

Output

+Inf false
Example (Int No Overflow) 

package main

import (
	"fmt"
	"github.com/chen3feng/safecast"
)

func main() {
	b, ok := safecast.To[byte](255)
	fmt.Print(b, ok)
}

Output

255 true
Example (Int Overflow) 

package main

import (
	"fmt"
	"github.com/chen3feng/safecast"
)

func main() {
	b, ok := safecast.To[byte](256)
	fmt.Print(b, ok)
}

Output

0 false
Example (Value In Range) 

package main

import (
	"fmt"
	"github.com/chen3feng/safecast"
)

func main() {
	n, ok := safecast.To[uint](1)
	fmt.Print(n, ok)
}

Output

1 true
Example (Value Out Of Range) 

package main

import (
	"fmt"
	"github.com/chen3feng/safecast"
)

func main() {
	n, ok := safecast.To[uint32](-1)
	fmt.Print(n, ok)
}

Output

4294967295 false

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GitHub

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