Add BoundedBitVec

2 files changed, 121 insertions, 0 deletions

diff --git a/chilbert/BoundedBitVec.hpp b/chilbert/BoundedBitVec.hpp
new file mode 100644
index 0000000..30ab21e
--- /dev/null
+++ b/chilbert/BoundedBitVec.hpp
@@ -0,0 +1,113 @@
+/*
+  Copyright (C) 2018 David Robillard <d@drobilla.net>
+  Copyright (C) 2006-2007 Chris Hamilton <chamilton@cs.dal.ca>
+
+  This program is free software: you can redistribute it and/or modify it under
+  the terms of the GNU General Public License as published by the Free Software
+  Foundation, either version 2 of the License, or (at your option) any later
+  version.
+
+  This program 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 General Public License for more
+  details.
+
+  You should have received a copy of the GNU General Public License along with
+  this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef CHILBERT_BOUNDEDBITVEC_HPP
+#define CHILBERT_BOUNDEDBITVEC_HPP
+
+#include "chilbert/BitVecIndex.hpp"
+#include "chilbert/BitVecIterator.hpp"
+#include "chilbert/BitVecMask.hpp"
+#include "chilbert/MultiBitVec.hpp"
+#include "chilbert/Operations.hpp"
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <cstddef>
+#include <cstdlib>
+#include <cstring>
+
+namespace chilbert {
+
+template <size_t MaxN>
+class BoundedBitVec : public MultiBitVec<BoundedBitVec<MaxN>>
+{
+public:
+	using Rack = typename MultiBitVec<BoundedBitVec<MaxN>>::Rack;
+
+	using MultiBitVec<BoundedBitVec<MaxN>>::bits_per_rack;
+
+	BoundedBitVec() = default;
+
+	explicit BoundedBitVec(const size_t bits)
+	  : m_size{bits}
+	{
+		assert(bits <= MaxN);
+	}
+
+	BoundedBitVec(const size_t bits, const Rack value)
+	  : BoundedBitVec{bits}
+	{
+		m_racks[0] = value;
+	}
+
+	/// Return the size in bits
+	size_t size() const { return m_size; }
+
+	/// Return a reference to the `index`th rack
+#ifndef NDEBUG
+	const auto& rack(const size_t index) const { return m_racks.at(index); }
+	auto&       rack(const size_t index) { return m_racks.at(index); }
+#else
+	const auto& rack(const size_t index) const { return m_racks[index]; }
+	auto&       rack(const size_t index) { return m_racks[index]; }
+#endif
+
+	/// Return a raw pointer to the racks
+	Rack*       data() { return m_racks.data(); }
+	const Rack* data() const { return m_racks.data(); }
+
+	/// Return the total size of all racks in bytes
+	size_t data_size() const { return num_racks() * sizeof(Rack); }
+
+	/// Return the number of racks
+	size_t num_racks() const { return calculate_num_racks(m_size); }
+
+private:
+	static constexpr size_t calculate_num_racks(const size_t bits)
+	{
+		return (std::max(bits, size_t(1)) + bits_per_rack - 1) / bits_per_rack;
+	}
+
+	std::array<Rack, calculate_num_racks(MaxN)> m_racks{};
+	size_t                                      m_size;
+};
+
+template <size_t MaxN>
+struct is_bitvec<BoundedBitVec<MaxN>>
+{
+	constexpr static bool value = true;
+};
+
+template <size_t MaxN>
+void
+gray_code(BoundedBitVec<MaxN>& value)
+{
+	gray_code(static_cast<MultiBitVec<BoundedBitVec<MaxN>>&>(value));
+}
+
+template <size_t MaxN>
+void
+gray_code_inv(BoundedBitVec<MaxN>& value)
+{
+	gray_code_inv(static_cast<MultiBitVec<BoundedBitVec<MaxN>>&>(value));
+}
+
+} // namespace chilbert
+
+#endif
diff --git a/chilbert/Hilbert.ipp b/chilbert/Hilbert.ipp
index 0b02fba..571166d 100644
--- a/chilbert/Hilbert.ipp
+++ b/chilbert/Hilbert.ipp
@@ -19,6 +19,7 @@
 #ifndef CHILBERT_ALGORITHM_HPP
 #define CHILBERT_ALGORITHM_HPP
 
+#include "chilbert/BoundedBitVec.hpp"
 #include "chilbert/DynamicBitVec.hpp"
 #include "chilbert/GrayCodeRank.hpp"
 #include "chilbert/Hilbert.hpp"
@@ -63,6 +64,13 @@ num_bits(const StaticBitVec<N>&, void* = nullptr)
 	return N;
 }
 
+template <size_t MaxN>
+size_t
+num_bits(const BoundedBitVec<MaxN>& vec, void* = nullptr)
+{
+	return vec.size();
+}
+
 /** Copy a range of bits from one field to the start of another.
  *
  * @param h Source bit field