github.com/n1ghtfa1l/go-vnt@v0.6.4-alpha.6/common/insert.go

// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package common

import "reflect"

func Insert(slice interface{}, pos int, value interface{}) interface{} {

	v := reflect.ValueOf(slice)
	insert := reflect.ValueOf(value)
	if insert.Len() == 0 {
		return v.Interface()
	}
	ne := reflect.MakeSlice(reflect.TypeOf(value), insert.Len(), insert.Len())
	for i := 0; i < insert.Len(); i++ {
		ne.Index(i).Set(insert.Index(i))
	}

	v = reflect.AppendSlice(v.Slice(0, pos), reflect.AppendSlice(ne, v.Slice(pos, v.Len())))

	return v.Interface()
}