/*
* Copyright (C) 2015 Benjamin Fry <benjaminfry@me.com>
*
* 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.
*/
//! Operation code for queries, updates, and responses
use From;
use *;
/// Operation code for queries, updates, and responses
///
/// [RFC 1035, DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION, November 1987](https://tools.ietf.org/html/rfc1035)
///
/// ```text
/// OPCODE A four bit field that specifies kind of query in this
/// message. This value is set by the originator of a query
/// and copied into the response. The values are:
///
/// 0 a standard query (QUERY)
///
/// 1 an inverse query (IQUERY)
///
/// 2 a server status request (STATUS)
///
/// 3-15 reserved for future use
/// ```
/// Convert from OpCode to u8
///
/// ```
/// use std::convert::From;
/// use trust_dns::op::op_code::OpCode;
///
/// let var: u8 = From::from(OpCode::Query);
/// assert_eq!(0, var);
///
/// let var: u8 = OpCode::Query.into();
/// assert_eq!(0, var);
/// ```
/// Convert from u8 to OpCode
///
/// ```
/// use std::convert::From;
/// use trust_dns::op::op_code::OpCode;
///
/// let var: OpCode = OpCode::from_u8(0).unwrap();
/// assert_eq!(OpCode::Query, var);
/// ```