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// Copyright 2015-2018 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_AXES_HPP
#define BOOST_HISTOGRAM_DETAIL_AXES_HPP
#include <array>
#include <boost/assert.hpp>
#include <boost/core/nvp.hpp>
#include <boost/histogram/axis/traits.hpp>
#include <boost/histogram/axis/variant.hpp>
#include <boost/histogram/detail/make_default.hpp>
#include <boost/histogram/detail/optional_index.hpp>
#include <boost/histogram/detail/static_if.hpp>
#include <boost/histogram/fwd.hpp>
#include <boost/mp11/algorithm.hpp>
#include <boost/mp11/list.hpp>
#include <boost/mp11/tuple.hpp>
#include <boost/mp11/utility.hpp>
#include <boost/throw_exception.hpp>
#include <stdexcept>
#include <string>
#include <tuple>
#include <type_traits>
/* Most of the histogram code is generic and works for any number of axes. Buffers with a
* fixed maximum capacity are used in some places, which have a size equal to the rank of
* a histogram. The buffers are statically allocated to improve performance, which means
* that they need a preset maximum capacity. 32 seems like a safe upper limit for the rank
* (you can nevertheless increase it here if necessary): the simplest non-trivial axis has
* 2 bins; even if counters are used which need only a byte of storage per bin, this still
* corresponds to 4 GB of storage.
*/
#ifndef BOOST_HISTOGRAM_DETAIL_AXES_LIMIT
#define BOOST_HISTOGRAM_DETAIL_AXES_LIMIT 32
#endif
namespace boost {
namespace histogram {
namespace detail {
template <class T>
unsigned axes_rank(const T& axes) {
using std::begin;
using std::end;
return static_cast<unsigned>(std::distance(begin(axes), end(axes)));
}
template <class... Ts>
constexpr unsigned axes_rank(const std::tuple<Ts...>&) {
return static_cast<unsigned>(sizeof...(Ts));
}
template <class T>
void throw_if_axes_is_too_large(const T& axes) {
if (axes_rank(axes) > BOOST_HISTOGRAM_DETAIL_AXES_LIMIT)
BOOST_THROW_EXCEPTION(
std::invalid_argument("length of axis vector exceeds internal buffers, "
"recompile with "
"-DBOOST_HISTOGRAM_DETAIL_AXES_LIMIT=<new max size> "
"to increase internal buffers"));
}
// tuple is never too large because internal buffers adapt to size of tuple
template <class... Ts>
void throw_if_axes_is_too_large(const std::tuple<Ts...>&) {}
template <unsigned N, class... Ts>
decltype(auto) axis_get(std::tuple<Ts...>& axes) {
return std::get<N>(axes);
}
template <unsigned N, class... Ts>
decltype(auto) axis_get(const std::tuple<Ts...>& axes) {
return std::get<N>(axes);
}
template <unsigned N, class T>
decltype(auto) axis_get(T& axes) {
return axes[N];
}
template <unsigned N, class T>
decltype(auto) axis_get(const T& axes) {
return axes[N];
}
template <class... Ts>
auto axis_get(std::tuple<Ts...>& axes, const unsigned i) {
constexpr auto S = sizeof...(Ts);
using V = mp11::mp_unique<axis::variant<Ts*...>>;
return mp11::mp_with_index<S>(i, [&axes](auto i) { return V(&std::get<i>(axes)); });
}
template <class... Ts>
auto axis_get(const std::tuple<Ts...>& axes, const unsigned i) {
constexpr auto S = sizeof...(Ts);
using V = mp11::mp_unique<axis::variant<const Ts*...>>;
return mp11::mp_with_index<S>(i, [&axes](auto i) { return V(&std::get<i>(axes)); });
}
template <class T>
decltype(auto) axis_get(T& axes, const unsigned i) {
return axes[i];
}
template <class T>
decltype(auto) axis_get(const T& axes, const unsigned i) {
return axes[i];
}
template <class... Ts, class... Us>
bool axes_equal(const std::tuple<Ts...>& ts, const std::tuple<Us...>& us) {
using namespace ::boost::mp11;
return static_if<std::is_same<mp_list<Ts...>, mp_list<Us...>>>(
[](const auto& ts, const auto& us) {
using N = mp_size<std::decay_t<decltype(ts)>>;
bool equal = true;
mp_for_each<mp_iota<N>>(
[&](auto I) { equal &= relaxed_equal(std::get<I>(ts), std::get<I>(us)); });
return equal;
},
[](const auto&, const auto&) { return false; }, ts, us);
}
template <class T, class... Us>
bool axes_equal(const T& t, const std::tuple<Us...>& u) {
using namespace ::boost::mp11;
if (t.size() != sizeof...(Us)) return false;
bool equal = true;
mp_for_each<mp_iota_c<sizeof...(Us)>>([&](auto I) { equal &= t[I] == std::get<I>(u); });
return equal;
}
template <class... Ts, class U>
bool axes_equal(const std::tuple<Ts...>& t, const U& u) {
return axes_equal(u, t);
}
template <class T, class U>
bool axes_equal(const T& t, const U& u) {
if (t.size() != u.size()) return false;
return std::equal(t.begin(), t.end(), u.begin());
}
template <class... Ts, class... Us>
void axes_assign(std::tuple<Ts...>& t, const std::tuple<Us...>& u) {
using namespace ::boost::mp11;
static_if<std::is_same<mp_list<Ts...>, mp_list<Us...>>>(
[](auto& a, const auto& b) { a = b; },
[](auto&, const auto&) {
BOOST_THROW_EXCEPTION(
std::invalid_argument("cannot assign axes, types do not match"));
},
t, u);
}
template <class... Ts, class U>
void axes_assign(std::tuple<Ts...>& t, const U& u) {
using namespace ::boost::mp11;
mp_for_each<mp_iota_c<sizeof...(Ts)>>([&](auto I) {
using T = mp_at_c<std::tuple<Ts...>, I>;
std::get<I>(t) = axis::get<T>(u[I]);
});
}
template <class T, class... Us>
void axes_assign(T& t, const std::tuple<Us...>& u) {
// resize instead of reserve, because t may not be empty and we want exact capacity
t.resize(sizeof...(Us));
using namespace ::boost::mp11;
mp_for_each<mp_iota_c<sizeof...(Us)>>([&](auto I) { t[I] = std::get<I>(u); });
}
template <typename T, typename U>
void axes_assign(T& t, const U& u) {
t.assign(u.begin(), u.end());
}
template <class Archive, class T>
void axes_serialize(Archive& ar, T& axes) {
ar& make_nvp("axes", axes);
}
template <class Archive, class... Ts>
void axes_serialize(Archive& ar, std::tuple<Ts...>& axes) {
// needed to keep serialization format backward compatible
struct proxy {
std::tuple<Ts...>& t;
void serialize(Archive& ar, unsigned /* version */) {
mp11::tuple_for_each(t, [&ar](auto& x) { ar& make_nvp("item", x); });
}
};
proxy p{axes};
ar& make_nvp("axes", p);
}
// create empty dynamic axis which can store any axes types from the argument
template <class T>
auto make_empty_dynamic_axes(const T& axes) {
return make_default(axes);
}
template <class... Ts>
auto make_empty_dynamic_axes(const std::tuple<Ts...>&) {
using namespace ::boost::mp11;
using L = mp_unique<axis::variant<Ts...>>;
// return std::vector<axis::variant<Axis0, Axis1, ...>> or std::vector<Axis0>
return std::vector<mp_if_c<(mp_size<L>::value == 1), mp_first<L>, L>>{};
}
template <class T>
void axis_index_is_valid(const T& axes, const unsigned N) {
BOOST_ASSERT_MSG(N < axes_rank(axes), "index out of range");
}
template <class Axes, class V>
void for_each_axis_impl(std::true_type, Axes&& axes, V&& v) {
for (auto&& a : axes) { axis::visit(std::forward<V>(v), a); }
}
template <class Axes, class V>
void for_each_axis_impl(std::false_type, Axes&& axes, V&& v) {
for (auto&& a : axes) std::forward<V>(v)(a);
}
template <class Axes, class V>
void for_each_axis(Axes&& a, V&& v) {
using namespace ::boost::mp11;
using T = mp_first<std::decay_t<Axes>>;
for_each_axis_impl(is_axis_variant<T>(), std::forward<Axes>(a), std::forward<V>(v));
}
template <class V, class... Axis>
void for_each_axis(const std::tuple<Axis...>& a, V&& v) {
mp11::tuple_for_each(a, std::forward<V>(v));
}
template <class V, class... Axis>
void for_each_axis(std::tuple<Axis...>& a, V&& v) {
mp11::tuple_for_each(a, std::forward<V>(v));
}
// total number of bins including *flow bins
template <class T>
std::size_t bincount(const T& axes) {
std::size_t n = 1;
for_each_axis(axes, [&n](const auto& a) {
const auto old = n;
const auto s = axis::traits::extent(a);
n *= s;
if (s > 0 && n < old) BOOST_THROW_EXCEPTION(std::overflow_error("bincount overflow"));
});
return n;
}
// initial offset for the linear index
template <class T>
std::size_t offset(const T& axes) {
std::size_t n = 0;
for_each_axis(axes, [&n, stride = static_cast<std::size_t>(1)](const auto& a) mutable {
if (axis::traits::options(a) & axis::option::growth)
n = invalid_index;
else if (n != invalid_index && axis::traits::options(a) & axis::option::underflow)
n += stride;
stride *= axis::traits::extent(a);
});
return n;
}
template <class T>
using buffer_size_impl = typename std::tuple_size<T>::type;
template <class T>
using buffer_size = mp11::mp_eval_or<
std::integral_constant<std::size_t, BOOST_HISTOGRAM_DETAIL_AXES_LIMIT>,
buffer_size_impl, T>;
template <class T, std::size_t N>
class sub_array : public std::array<T, N> {
using base_type = std::array<T, N>;
public:
explicit sub_array(std::size_t s) noexcept(
std::is_nothrow_default_constructible<T>::value)
: size_(s) {
BOOST_ASSERT_MSG(size_ <= N, "requested size exceeds size of static buffer");
}
sub_array(std::size_t s,
const T& value) noexcept(std::is_nothrow_copy_constructible<T>::value)
: size_(s) {
BOOST_ASSERT_MSG(size_ <= N, "requested size exceeds size of static buffer");
std::array<T, N>::fill(value);
}
// need to override both versions of std::array
auto end() noexcept { return base_type::begin() + size_; }
auto end() const noexcept { return base_type::begin() + size_; }
auto size() const noexcept { return size_; }
private:
std::size_t size_;
};
template <class U, class T>
using stack_buffer = sub_array<U, buffer_size<T>::value>;
// make default-constructed buffer (no initialization for POD types)
template <class U, class T>
auto make_stack_buffer(const T& t) {
return stack_buffer<U, T>(axes_rank(t));
}
// make buffer with elements initialized to v
template <class U, class T, class V>
auto make_stack_buffer(const T& t, V&& v) {
return stack_buffer<U, T>(axes_rank(t), std::forward<V>(v));
}
template <class T>
using has_underflow =
decltype(axis::traits::static_options<T>::test(axis::option::underflow));
template <class T>
using is_growing = decltype(axis::traits::static_options<T>::test(axis::option::growth));
template <class T>
using is_not_inclusive = mp11::mp_not<axis::traits::static_is_inclusive<T>>;
// for vector<T>
template <class T>
struct axis_types_impl {
using type = mp11::mp_list<std::decay_t<T>>;
};
// for vector<variant<Ts...>>
template <class... Ts>
struct axis_types_impl<axis::variant<Ts...>> {
using type = mp11::mp_list<std::decay_t<Ts>...>;
};
// for tuple<Ts...>
template <class... Ts>
struct axis_types_impl<std::tuple<Ts...>> {
using type = mp11::mp_list<std::decay_t<Ts>...>;
};
template <class T>
using axis_types =
typename axis_types_impl<mp11::mp_if<is_vector_like<T>, mp11::mp_first<T>, T>>::type;
template <template <class> class Trait, class Axes>
using has_special_axis = mp11::mp_any_of<axis_types<Axes>, Trait>;
template <class Axes>
using has_growing_axis = mp11::mp_any_of<axis_types<Axes>, is_growing>;
template <class Axes>
using has_non_inclusive_axis = mp11::mp_any_of<axis_types<Axes>, is_not_inclusive>;
template <class T>
constexpr std::size_t type_score() {
return sizeof(T) *
(std::is_integral<T>::value ? 1 : std::is_floating_point<T>::value ? 10 : 100);
}
// arbitrary ordering of types
template <class T, class U>
using type_less = mp11::mp_bool<(type_score<T>() < type_score<U>())>;
template <class Axes>
using value_types = mp11::mp_sort<
mp11::mp_unique<mp11::mp_transform<axis::traits::value_type, axis_types<Axes>>>,
type_less>;
} // namespace detail
} // namespace histogram
} // namespace boost
#endif