// str returns s, interned.
func (c *Corpus) str(s string) string {
	if s == "" {
		return ""
	}
	if s, ok := c.strs[s]; ok {
		return s
	}
	if c.strs == nil {
		c.strs = make(map[string]string)
	}
	c.strs[s] = s
	return s
}

package main

import (
	"fmt"
	"reflect"
	"strconv"
	"unsafe"
)

type CamliType string

const (
	Type12 CamliType = "12"
)

func stringptr(s string) uintptr {
	return (*reflect.StringHeader)(unsafe.Pointer(&s)).Data
}

type stringInterner map[string]string

func (si stringInterner) Intern(s string) string {
	if interned, ok := si[s]; ok {
		return interned
	}
	si[s] = s
	return s
}

func main() {
	interner := stringInterner{}

	s1 := interner.Intern(string(Type12))
	s2 := interner.Intern(string(CamliType(strconv.Itoa(12))))

	fmt.Println(stringptr(s1) == stringptr(s2))
}