func (z *Int) String() string {
	if z == nil {
		return "nil"
	}
	z.doinit()
	p := C.mpz_get_str(nil, 10, &z.i[0])
	s := C.GoString(p)
	C.free(unsafe.Pointer(p))
	return s
}

func (z *Int) destroy() {
	if z.init {
		C.mpz_clear(&z.i[0])
	}
	z.init = false
}

/*
 * arithmetic
 */

// Add sets z = x + y and returns z.
func (z *Int) Add(x, y *Int) *Int {
	x.doinit()

package tests_test

import (
	"regexp"
	"strings"
	"testing"
	"time"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	. "gorm.io/gorm/utils/tests"
)

func TestRow(t *testing.T) {
	user1 := User{Name: "RowUser1", Age: 1}
	user2 := User{Name: "RowUser2", Age: 10}
	user3 := User{Name: "RowUser3", Age: 20}
	DB.Save(&user1).Save(&user2).Save(&user3)

	row := DB.Table("users").Where("name = ?", user2.Name).Select("age").Row()