Tagged Unions for Go

Always wanted to use tagged unions in Go? Thought it wasn't supported? well, it is!

Try it out https://go.dev/play/p/Pp06ahQrt5-

	package main

	import (
		"fmt"
		"math"

		"github.com/splizard/tagged"
	)

	// Each field in the struct, denotes a possible value for the union.
	// A Float can either be a Bits32 (float32) or a Bits64 (float64).
	// Up to 65535 fields are supported, of any type, make sure to use
	// an appropriate buffer size/value, otherwise [tagged.Fields] will
	// panic. If any value contains pointers, then the buffer type must
	// be [any].
	type Float tagged.Union[[8]byte, struct {
		Bits32 tagged.As[Float, float32]
		Bits64 tagged.As[Float, float64]
	}]

	// FloatWith is the name of our accessor value. The heavy reflection
	// is completed in advance and cached in this value so that we can
	// work with [Float] union values efficiently.
	var FloatWith = tagged.Fields(Float{})

	func check(value Float) {
		switch tagged.FieldOf(value) {
		case FloatWith.Bits32.Field:
			var f32 float32 = FloatWith.Bits32.Get(value)
			fmt.Println("value is a float32", f32)
		case FloatWith.Bits64.Field:
			var f64 float64 = FloatWith.Bits64.Get(value)
			fmt.Println("value is a float64", f64)
		}
	}

	func main() {
		var pi Float
		pi = FloatWith.Bits32.New(math.Pi)
		check(pi)
		pi = FloatWith.Bits64.New(math.Pi)
		check(pi)
	}