// Copyright (c) 2000-2020, Heiko Bauke
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#if !(defined TRNG_GENERATE_CANONICAL_HPP)

#define TRNG_GENERATE_CANONICAL_HPP

#include <type_traits>
#include <trng/cuda.hpp>
#include <trng/limits.hpp>
#include <trng/math.hpp>
#include <trng/utility.hpp>

namespace trng {

  template<typename result_type, typename R>
  TRNG_CUDA_ENABLE result_type generate_canonical(R &);

  namespace detail {

    template<typename result_type, typename R>
    TRNG_CUDA_ENABLE inline
        typename std::enable_if<std::is_floating_point<result_type>::value, result_type>::type
        generate_canonical_impl(R &r, result_type) {
      return utility::uniformoo<result_type>(r);
    }

    template<typename result_type, typename R>
    TRNG_CUDA_ENABLE inline
        typename std::enable_if<math::numeric_limits<result_type>::is_integer,
                                result_type>::type
        generate_canonical_impl(R &r, result_type) {
      return static_cast<result_type>(
          math::floor(utility::uniformco<double>(r) *
                      (static_cast<double>(R::max) - static_cast<double>(R::min) + 1.0)));
    }

  }  // namespace detail

  template<typename result_type, typename R>
  TRNG_CUDA_ENABLE result_type generate_canonical(R &g) {
    return detail::generate_canonical_impl(g, result_type());
  }

}  // namespace trng

#endif
