// Copyright 2018 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package tcp

import (
	"reflect"
	"unsafe"
)

// optionsToArray converts a slice of capacity >-= maxOptionSize to an array.
//
// optionsToArray panics if the capacity of options is smaller than
// maxOptionSize.
func optionsToArray(options []byte) *[maxOptionSize]byte {
	// Reslice to full capacity.
	options = options[0:maxOptionSize]
	return (*[maxOptionSize]byte)(unsafe.Pointer((*reflect.SliceHeader)(unsafe.Pointer(&options)).Data))
}