portald/floppy/floppy.go

package floppy

import (
	"io"

	"golang.org/x/sync/errgroup"
)

func Floppy(a, b io.ReadWriter) error {
	var g errgroup.Group
	g.Go(func() error {
		_, err := io.Copy(a, b)
		return err
	})
	g.Go(func() error {
		_, err := io.Copy(b, a)
		return err
	})
	return g.Wait()
}