//===-- rosa/support/sequence.hpp -------------------------------*- C++ -*-===//
//
//                                 The RoSA Framework
//
//===----------------------------------------------------------------------===//
///
/// \file rosa/support/sequence.hpp
///
/// \author David Juhasz (david.juhasz@tuwien.ac.at)
///
/// \date 2017
///
/// \brief Template facilities to statically generate a sequence of numbers.
///
//===----------------------------------------------------------------------===//

#ifndef ROSA_SUPPORT_SEQUENCE_HPP
#define ROSA_SUPPORT_SEQUENCE_HPP

#include <cstddef>

namespace rosa {

/// \defgroup Seq Implementation of rosa::Seq
///
/// Facility to statically generate sequences of numbers.
///
///@{

/// Template with an empty struct to store a sequence of numbers in compile time
/// as template arguments.
///
/// Generate a sequence of numbers from `0` up to (including) `(N - 1)` like
/// \code
/// typename GenSeq<N>::Type
/// \endcode
template <size_t...> struct Seq {};

/// Sequence generator, the general case when counting down by extending the
/// sequence.
template <size_t N, size_t... S> struct GenSeq : GenSeq<N - 1, N - 1, S...> {};

/// Sequence generator, the terminal case when storing the generated sequence
/// into \c Seq.
template <size_t... S> struct GenSeq<0, S...> { using Type = Seq<S...>; };

///@}

/// Convenience template alias for using \c rosa::GenSeq to obtain an instance
    /// of \c rosa::Seq.
    ///
    /// \see \c rosa::Seq and \c rosa::GenSeq
    template <size_t... S> using seq_t = typename GenSeq<S...>::Type;
} // End namespace rosa

#endif // ROSA_SUPPORT_SEQUENCE_HPP