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// Copyright 2019 Hans Dembinski
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at


#include <utility>

namespace boost {
namespace histogram {

/** Weight holder and type envelope.

  You should not construct these directly, use the weight() helper function.

  @tparam Underlying arithmetic type.
template <class T>
struct weight_type {
  /// Access underlying value.
  T value;

  /// Allow implicit conversions of types when the underlying value type allows them.
  template <class U>
  operator weight_type<U>() const {
    return weight_type<U>{static_cast<U>(value)};

/** Helper function to mark argument as weight.

  @param t argument to be forward to the histogram.
template <class T>
auto weight(T&& t) noexcept {
  return weight_type<T>{std::forward<T>(t)};

} // namespace histogram
} // namespace boost