Repo created

3party/succinct/nibble_vector.hpp

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+#pragma once
+
+#include <vector>
+
+#include <boost/range.hpp>
+
+#include "succinct/mappable_vector.hpp"
+
+namespace succinct {
+
+    class nibble_vector {
+    public:
+        nibble_vector()
+            : m_size(0)
+        {}
+
+        template <class Range>
+        nibble_vector(Range const& from)
+            : m_size(0)
+        {
+            std::vector<uint8_t> nibbles;
+            bool parity = 0;
+            uint8_t cur_byte = 0;
+            for (typename boost::range_const_iterator<Range>::type iter = boost::begin(from);
+                 iter != boost::end(from);
+                 ++iter) {
+                assert(*iter < 16);
+                cur_byte |= *iter << (parity * 4);
+                parity = !parity;
+                if (!parity) {
+                    nibbles.push_back(cur_byte);
+                    cur_byte = 0;
+                }
+                ++m_size;
+            }
+            if (parity) {
+                nibbles.push_back(cur_byte);
+            }
+            m_nibbles.steal(nibbles);
+        }
+
+        template <typename Visitor>
+        void map(Visitor& visit) {
+            visit
+                (m_size, "m_size")
+                (m_nibbles, "m_nibbles");
+        }
+
+        void swap(nibble_vector& other) {
+            std::swap(other.m_size, m_size);
+            other.m_nibbles.swap(m_nibbles);
+        }
+
+        size_t size() const {
+            return m_size;
+        }
+
+        uint8_t operator[](uint64_t pos) const {
+            assert(pos < m_size);
+            return (m_nibbles[pos / 2] >> ((pos % 2) * 4)) & 0x0F;
+        }
+
+    protected:
+        size_t m_size;
+        mapper::mappable_vector<uint8_t> m_nibbles;
+    };
+
+}