Added thirdparty: boost library

thirdparty/include/boost/histogram/detail/large_int.hpp

@@ -0,0 +1,255 @@
+// Copyright 2018-2019 Hans Dembinski
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_HISTOGRAM_DETAIL_LARGE_INT_HPP
+#define BOOST_HISTOGRAM_DETAIL_LARGE_INT_HPP
+
+#include <boost/histogram/detail/operators.hpp>
+#include <boost/histogram/detail/safe_comparison.hpp>
+#include <boost/mp11/algorithm.hpp>
+#include <boost/mp11/function.hpp>
+#include <boost/mp11/list.hpp>
+#include <boost/mp11/utility.hpp>
+#include <cassert>
+#include <cmath>
+#include <cstdint>
+#include <limits>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+namespace boost {
+namespace histogram {
+namespace detail {
+
+template <class T>
+using is_unsigned_integral = mp11::mp_and<std::is_integral<T>, std::is_unsigned<T>>;
+
+template <class T>
+bool safe_increment(T& t) {
+  if (t < (std::numeric_limits<T>::max)()) {
+    ++t;
+    return true;
+  }
+  return false;
+}
+
+template <class T, class U>
+bool safe_radd(T& t, const U& u) {
+  static_assert(is_unsigned_integral<T>::value, "T must be unsigned integral type");
+  static_assert(is_unsigned_integral<U>::value, "T must be unsigned integral type");
+  if (static_cast<T>((std::numeric_limits<T>::max)() - t) >= u) {
+    t += static_cast<T>(u); // static_cast to suppress conversion warning
+    return true;
+  }
+  return false;
+}
+
+// An integer type which can grow arbitrarily large (until memory is exhausted).
+// Use boost.multiprecision.cpp_int in your own code, it is much more sophisticated.
+// We use it only to reduce coupling between boost libs.
+template <class Allocator>
+struct large_int : totally_ordered<large_int<Allocator>, large_int<Allocator>>,
+                   partially_ordered<large_int<Allocator>, void> {
+  explicit large_int(const Allocator& a = {}) : data(1, 0, a) {}
+  explicit large_int(std::uint64_t v, const Allocator& a = {}) : data(1, v, a) {}
+
+  large_int(const large_int&) = default;
+  large_int& operator=(const large_int&) = default;
+  large_int(large_int&&) = default;
+  large_int& operator=(large_int&&) = default;
+
+  large_int& operator=(std::uint64_t o) {
+    data = decltype(data)(1, o);
+    return *this;
+  }
+
+  large_int& operator++() {
+    assert(data.size() > 0u);
+    std::size_t i = 0;
+    while (!safe_increment(data[i])) {
+      data[i] = 0;
+      ++i;
+      if (i == data.size()) {
+        data.push_back(1);
+        break;
+      }
+    }
+    return *this;
+  }
+
+  large_int& operator+=(const large_int& o) {
+    if (this == &o) {
+      auto tmp{o};
+      return operator+=(tmp);
+    }
+    bool carry = false;
+    std::size_t i = 0;
+    for (std::uint64_t oi : o.data) {
+      auto& di = maybe_extend(i);
+      if (carry) {
+        if (safe_increment(oi))
+          carry = false;
+        else {
+          ++i;
+          continue;
+        }
+      }
+      if (!safe_radd(di, oi)) {
+        add_remainder(di, oi);
+        carry = true;
+      }
+      ++i;
+    }
+    while (carry) {
+      auto& di = maybe_extend(i);
+      if (safe_increment(di)) break;
+      di = 0;
+      ++i;
+    }
+    return *this;
+  }
+
+  large_int& operator+=(std::uint64_t o) {
+    assert(data.size() > 0u);
+    if (safe_radd(data[0], o)) return *this;
+    add_remainder(data[0], o);
+    // carry the one, data may grow several times
+    std::size_t i = 1;
+    while (true) {
+      auto& di = maybe_extend(i);
+      if (safe_increment(di)) break;
+      di = 0;
+      ++i;
+    }
+    return *this;
+  }
+
+  explicit operator double() const noexcept {
+    assert(data.size() > 0u);
+    double result = static_cast<double>(data[0]);
+    std::size_t i = 0;
+    while (++i < data.size())
+      result += static_cast<double>(data[i]) * std::pow(2.0, i * 64);
+    return result;
+  }
+
+  bool operator<(const large_int& o) const noexcept {
+    assert(data.size() > 0u);
+    assert(o.data.size() > 0u);
+    // no leading zeros allowed
+    assert(data.size() == 1 || data.back() > 0u);
+    assert(o.data.size() == 1 || o.data.back() > 0u);
+    if (data.size() < o.data.size()) return true;
+    if (data.size() > o.data.size()) return false;
+    auto s = data.size();
+    while (s > 0u) {
+      --s;
+      if (data[s] < o.data[s]) return true;
+      if (data[s] > o.data[s]) return false;
+    }
+    return false; // args are equal
+  }
+
+  bool operator==(const large_int& o) const noexcept {
+    assert(data.size() > 0u);
+    assert(o.data.size() > 0u);
+    // no leading zeros allowed
+    assert(data.size() == 1 || data.back() > 0u);
+    assert(o.data.size() == 1 || o.data.back() > 0u);
+    if (data.size() != o.data.size()) return false;
+    return std::equal(data.begin(), data.end(), o.data.begin());
+  }
+
+  template <class U>
+  std::enable_if_t<std::is_integral<U>::value, bool> operator<(
+      const U& o) const noexcept {
+    assert(data.size() > 0u);
+    return data.size() == 1 && safe_less()(data[0], o);
+  }
+
+  template <class U>
+  std::enable_if_t<std::is_integral<U>::value, bool> operator>(
+      const U& o) const noexcept {
+    assert(data.size() > 0u);
+    assert(data.size() == 1 || data.back() > 0u); // no leading zeros allowed
+    return data.size() > 1 || safe_less()(o, data[0]);
+  }
+
+  template <class U>
+  std::enable_if_t<std::is_integral<U>::value, bool> operator==(
+      const U& o) const noexcept {
+    assert(data.size() > 0u);
+    return data.size() == 1 && safe_equal()(data[0], o);
+  }
+
+  template <class U>
+  std::enable_if_t<std::is_floating_point<U>::value, bool> operator<(
+      const U& o) const noexcept {
+    return operator double() < o;
+  }
+
+  template <class U>
+  std::enable_if_t<std::is_floating_point<U>::value, bool> operator>(
+      const U& o) const noexcept {
+    return operator double() > o;
+  }
+
+  template <class U>
+  std::enable_if_t<std::is_floating_point<U>::value, bool> operator==(
+      const U& o) const noexcept {
+    return operator double() == o;
+  }
+
+  template <class U>
+  std::enable_if_t<
+      (!std::is_arithmetic<U>::value && std::is_convertible<U, double>::value), bool>
+  operator<(const U& o) const noexcept {
+    return operator double() < o;
+  }
+
+  template <class U>
+  std::enable_if_t<
+      (!std::is_arithmetic<U>::value && std::is_convertible<U, double>::value), bool>
+  operator>(const U& o) const noexcept {
+    return operator double() > o;
+  }
+
+  template <class U>
+  std::enable_if_t<
+      (!std::is_arithmetic<U>::value && std::is_convertible<U, double>::value), bool>
+  operator==(const U& o) const noexcept {
+    return operator double() == o;
+  }
+
+  std::uint64_t& maybe_extend(std::size_t i) {
+    while (i >= data.size()) data.push_back(0);
+    return data[i];
+  }
+
+  static void add_remainder(std::uint64_t& d, const std::uint64_t o) noexcept {
+    assert(d > 0u);
+    // in decimal system it would look like this:
+    // 8 + 8 = 6 = 8 - (9 - 8) - 1
+    // 9 + 1 = 0 = 9 - (9 - 1) - 1
+    auto tmp = (std::numeric_limits<std::uint64_t>::max)();
+    tmp -= o;
+    --d -= tmp;
+  }
+
+  template <class Archive>
+  void serialize(Archive& ar, unsigned /* version */) {
+    ar& make_nvp("data", data);
+  }
+
+  std::vector<std::uint64_t, Allocator> data;
+};
+
+} // namespace detail
+} // namespace histogram
+} // namespace boost
+
+#endif