ExpressionTraits.h

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// -*- c++ -*-
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#ifndef NDARRAY_ExpressionTraits_h_INCLUDED
#define NDARRAY_ExpressionTraits_h_INCLUDED

#include "ndarray_fwd.h"
#include <boost/static_assert.hpp>

namespace ndarray {

template <typename Expression_> struct ExpressionTraits {
    typedef boost::mpl::true_ IsScalar;
};

#ifndef GCC_45

template <typename Operand, typename UnaryFunction, int N>
struct ExpressionTraits< detail::UnaryOpExpression<Operand,UnaryFunction,N> > {
    typedef typename UnaryFunction::result_type Element;
    typedef typename ExpressionTraits<Operand>::ND ND;
    typedef detail::UnaryOpIterator<Operand,UnaryFunction> Iterator;
    typedef detail::UnaryOpExpression<
        typename ExpressionTraits<Operand>::Reference,UnaryFunction,N-1
        > Value;
    typedef Value Reference;
    typedef boost::mpl::false_ IsScalar;
};

template <typename Operand, typename UnaryFunction>
struct ExpressionTraits< detail::UnaryOpExpression<Operand,UnaryFunction,1> > {
    typedef typename UnaryFunction::result_type Element;
    typedef typename ExpressionTraits<Operand>::ND ND;
    typedef detail::UnaryOpIterator<Operand,UnaryFunction> Iterator;
    typedef typename boost::remove_const<Element>::type Value;
    typedef Value const Reference;
    typedef boost::mpl::false_ IsScalar;
};

template <typename Operand1, typename Operand2, typename BinaryFunction, int N>
struct ExpressionTraits< detail::BinaryOpExpression<Operand1,Operand2,BinaryFunction,N> > {
    typedef typename BinaryFunction::result_type Element;
    typedef typename ExpressionTraits<Operand1>::ND ND;
    typedef detail::BinaryOpIterator<Operand1,Operand2,BinaryFunction> Iterator;
    typedef detail::BinaryOpExpression<
        typename ExpressionTraits<Operand1>::Reference,
        typename ExpressionTraits<Operand2>::Reference,
        BinaryFunction, N-1 > Reference;
    typedef Reference Value;
    typedef boost::mpl::false_ IsScalar;
    BOOST_STATIC_ASSERT((ND::value == ExpressionTraits<Operand2>::ND::value));
};

template <typename Operand1, typename Operand2, typename BinaryFunction>
struct ExpressionTraits< detail::BinaryOpExpression<Operand1,Operand2,BinaryFunction,1> > {
    typedef typename BinaryFunction::result_type Element;
    typedef typename ExpressionTraits<Operand1>::ND ND;
    typedef detail::BinaryOpIterator<Operand1,Operand2,BinaryFunction> Iterator;
    typedef typename boost::remove_const<Element>::type Value;
    typedef Value const Reference;
    typedef boost::mpl::false_ IsScalar;
    BOOST_STATIC_ASSERT((ND::value == ExpressionTraits<Operand2>::ND::value));
};

#endif // GCC_45

} // namespace ndarray

#endif // !NDARRAY_ExpressionTraits_h_INCLUDED