// Copyright 2012 Aaron Jacobs. All Rights Reserved.
// Author: aaronjjacobs@gmail.com (Aaron Jacobs)
//
// 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 common

// Msb returns the most significant bit of the supplied data (which must be
// non-empty). This is the MSB(L) function of RFC 4493.
func Msb(buf []byte) uint8 {
	if len(buf) == 0 {
		panic("msb requires non-empty buffer.")
	}

	return buf[0] >> 7
}