libcruft-util/hash/table.hpp

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/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2019 Danny Robson <danny@nerdcruft.net>
*/
#pragma once
#include "../std.hpp"
///////////////////////////////////////////////////////////////////////////////
namespace cruft::hash {
/// Provide a trivial static mapping from a ValueT to a ResultT.
///
/// We guarantee that all outputs are:
/// * unique
/// * are unbiased at every bit offset
///
/// Specialisations are provided for u08, u16, u32, and u64 outputs with
/// u08 inputs. If further flexibility is required we can move the
/// implementation into the header.
///
/// \tparam ResultT The output of the 'hash' function.
/// \tparam WordT The input to the 'hash' function.
template <typename ResultT, typename WordT = u08>
class table {
public:
ResultT operator() (WordT const) const noexcept;
};
}