ladybird/AK/Hex.h
Lenny Maiorani d462a56163 AK/Hex: Decode hex digit in constexpr context
Problem:
- Hex digit decoding is not `constexpr`, but can be.

Solution:
- Move the body of the function to the header and decorate with
  `constexpr`.
- Provide tests for run-time and compile-time evaluation.
2021-04-18 22:09:25 +02:00

55 lines
1.9 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/ByteBuffer.h>
#include <AK/Optional.h>
#include <AK/String.h>
#include <AK/StringView.h>
namespace AK {
constexpr u8 decode_hex_digit(char digit)
{
if (digit >= '0' && digit <= '9')
return digit - '0';
if (digit >= 'a' && digit <= 'f')
return 10 + (digit - 'a');
if (digit >= 'A' && digit <= 'F')
return 10 + (digit - 'A');
return 255;
}
Optional<ByteBuffer> decode_hex(const StringView&);
String encode_hex(ReadonlyBytes);
}
using AK::decode_hex;
using AK::decode_hex_digit;
using AK::encode_hex;