goldberg_emulator/overlay_experimental/System/StringSwitch.hpp

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2022-08-05 08:06:42 +02:00
/*
* Copyright (C) Nemirtingas
* This file is part of System.
*
* System 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.
*
* System 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 System; if not, see
* <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <cstdint>
#include <string>
#include "SystemDetector.h"
#include "StringView.hpp"
namespace System {
namespace StringSwitch {
#if defined(SYSTEM_ARCH_X86)
using hash_type = uint32_t;
#else
using hash_type = uint64_t;
#endif
namespace Detail {
constexpr char lower_char(char c) { return ((c >= 'A' && c <= 'Z') ? c + 32 : c); }
}
// switch case on a string
constexpr hash_type Hash(const char* input, size_t len) { return (len > 0 ? static_cast<hash_type>(*input) + 33 * Hash(input + 1, len - 1) : 5381); }
template<size_t N>
constexpr hash_type Hash(const char(&input)[N]) { return Hash(input, N-1); }
constexpr hash_type Hash(System::StringView sv) { return Hash(sv.data(), sv.length()); }
inline hash_type Hash(const std::string& input) { return Hash(input.c_str(), input.length()); }
constexpr hash_type IHash(const char* input, size_t len) { return (len > 0 ? static_cast<hash_type>(Detail::lower_char(*input)) + 33 * IHash(input + 1, len - 1) : 5381); }
template<size_t N>
constexpr inline hash_type IHash(const char(&input)[N]) { return IHash(input, N - 1); }
constexpr hash_type IHash(System::StringView sv) { return IHash(sv.data(), sv.length()); }
inline hash_type IHash(const std::string& input) { return IHash(input.c_str(), input.length()); }
}
}