example.go

// #########################################
// rest/get.go
// #########################################

// This is working but its not what i want.
func GET(c echo.Context) error {
   // do something
}

// This is not working.
// Getting following error: cannot use GET (type func(interface {})) as type echo.HandlerFunc in argument to e.GET
// I thought i can pass GET function everything when it has a empty interface, what im doing wrong?
func GET(c interface{}){
   // do something
}

// maybe im doing everything wrong?

// #########################################
// index.go
// #########################################

package main

import (
	"github.com/labstack/echo"
	"github.com/serkansipahi/bitcollage/rest"
)

func main() {

	e := echo.New()

	e.GET("/*", rest.GET)
	e.Logger.Fatal(e.Start(":1323"))

}

All that's left is refer to documentation on usage, and usage does seem to work as recommended.

@fubarhouse thank you. Now its clearer to me. I think what i want is not possible as you had described.

func GET(c interface{}){
   
}