vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/numeric/ublas/operation/begin.hpp

319 lines
11 KiB
C++

/**
* -*- c++ -*-
*
* \file begin.hpp
*
* \brief The \c begin operation.
*
* Copyright (c) 2009, Marco Guazzone
*
* 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)
*
* \author Marco Guazzone, marco.guazzone@gmail.com
*/
#ifndef BOOST_NUMERIC_UBLAS_OPERATION_BEGIN_HPP
#define BOOST_NUMERIC_UBLAS_OPERATION_BEGIN_HPP
#include <boost/numeric/ublas/expression_types.hpp>
#include <boost/numeric/ublas/fwd.hpp>
#include <boost/numeric/ublas/traits/const_iterator_type.hpp>
#include <boost/numeric/ublas/traits/iterator_type.hpp>
namespace boost { namespace numeric { namespace ublas {
namespace detail {
/**
* \brief Auxiliary class for implementing the \c begin operation.
* \tparam CategoryT The expression category type (e.g., vector_tag).
* \tparam TagT The dimension type tag (e.g., tag::major).
* \tparam OrientationT The orientation category type (e.g., row_major_tag).
*/
template <typename CategoryT, typename TagT=void, typename OrientationT=void>
struct begin_impl;
/// \brief Specialization of \c begin_impl for iterating vector expressions.
template <>
struct begin_impl<vector_tag,void,void>
{
/**
* \brief Return an iterator to the first element of the given vector
* expression.
* \tparam ExprT A model of VectorExpression type.
* \param e A vector expression.
* \return An iterator over the given vector expression.
*/
template <typename ExprT>
static typename ExprT::iterator apply(ExprT& e)
{
return e.begin();
}
/**
* \brief Return a const iterator to the first element of the given vector
* expression.
* \tparam ExprT A model of VectorExpression type.
* \param e A vector expression.
* \return A const iterator to the first element of the given vector
* expression.
*/
template <typename ExprT>
static typename ExprT::const_iterator apply(ExprT const& e)
{
return e.begin();
}
};
/// \brief Specialization of \c begin_impl for iterating matrix expressions with
/// a row-major orientation over the major dimension.
template <>
struct begin_impl<matrix_tag,tag::major,row_major_tag>
{
/**
* \brief Return an iterator to the first element of the given row-major
* matrix expression over the major dimension.
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return An iterator over the major dimension of the given matrix
* expression.
*/
template <typename ExprT>
static typename ExprT::iterator1 apply(ExprT& e)
{
return e.begin1();
}
/**
* \brief Return a const iterator to the first element of the given
* row-major matrix expression over the major dimension.
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return A const iterator over the major dimension of the given matrix
* expression.
*/
template <typename ExprT>
static typename ExprT::const_iterator1 apply(ExprT const& e)
{
return e.begin1();
}
};
/// \brief Specialization of \c begin_impl for iterating matrix expressions with
/// a column-major orientation over the major dimension.
template <>
struct begin_impl<matrix_tag,tag::major,column_major_tag>
{
/**
* \brief Return an iterator to the first element of the given column-major
* matrix expression over the major dimension.
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return An iterator over the major dimension of the given matrix
* expression.
*/
template <typename ExprT>
static typename ExprT::iterator2 apply(ExprT& e)
{
return e.begin2();
}
/**
* \brief Return a const iterator to the first element of the given
* column-major matrix expression over the major dimension.
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return A const iterator over the major dimension of the given matrix
* expression.
*/
template <typename ExprT>
static typename ExprT::const_iterator2 apply(ExprT const& e)
{
return e.begin2();
}
};
/// \brief Specialization of \c begin_impl for iterating matrix expressions with
/// a row-major orientation over the minor dimension.
template <>
struct begin_impl<matrix_tag,tag::minor,row_major_tag>
{
/**
* \brief Return an iterator to the first element of the given row-major
* matrix expression over the minor dimension.
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return An iterator over the minor dimension of the given matrix
* expression.
*/
template <typename ExprT>
static typename ExprT::iterator2 apply(ExprT& e)
{
return e.begin2();
}
/**
* \brief Return a const iterator to the first element of the given
* row-major matrix expression over the minor dimension.
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return A const iterator over the minor dimension of the given matrix
* expression.
*/
template <typename ExprT>
static typename ExprT::const_iterator2 apply(ExprT const& e)
{
return e.begin2();
}
};
/// \brief Specialization of \c begin_impl for iterating matrix expressions with
/// a column-major orientation over the minor dimension.
template <>
struct begin_impl<matrix_tag,tag::minor,column_major_tag>
{
/**
* \brief Return an iterator to the first element of the given column-major
* matrix expression over the minor dimension.
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return An iterator over the minor dimension of the given matrix
* expression.
*/
template <typename ExprT>
static typename ExprT::iterator1 apply(ExprT& e)
{
return e.begin1();
}
/**
* \brief Return a const iterator to the first element of the given
* column-major matrix expression over the minor dimension.
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return A const iterator over the minor dimension of the given matrix
* expression.
*/
template <typename ExprT>
static typename ExprT::const_iterator1 apply(ExprT const& e)
{
return e.begin1();
}
};
} // Namespace detail
/**
* \brief An iterator to the first element of the given vector expression.
* \tparam ExprT A model of VectorExpression type.
* \param e A vector expression.
* \return An iterator to the first element of the given vector expression.
*/
template <typename ExprT>
BOOST_UBLAS_INLINE
typename ExprT::iterator begin(vector_expression<ExprT>& e)
{
return detail::begin_impl<typename ExprT::type_category>::apply(e());
}
/**
* \brief A const iterator to the first element of the given vector expression.
* \tparam ExprT A model of VectorExpression type.
* \param e A vector expression.
* \return A const iterator to the first element of the given vector expression.
*/
template <typename ExprT>
BOOST_UBLAS_INLINE
typename ExprT::const_iterator begin(vector_expression<ExprT> const& e)
{
return detail::begin_impl<typename ExprT::type_category>::apply(e());
}
/**
* \brief An iterator to the first element of the given matrix expression
* according to its orientation.
* \tparam DimTagT A dimension tag type (e.g., tag::major).
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return An iterator to the first element of the given matrix expression
* according to its orientation.
*/
template <typename TagT, typename ExprT>
BOOST_UBLAS_INLINE
typename iterator_type<ExprT,TagT>::type begin(matrix_expression<ExprT>& e)
{
return detail::begin_impl<typename ExprT::type_category, TagT, typename ExprT::orientation_category>::apply(e());
}
/**
* \brief A const iterator to the first element of the given matrix expression
* according to its orientation.
* \tparam TagT A dimension tag type (e.g., tag::major).
* \tparam ExprT A model of MatrixExpression type.
* \param e A matrix expression.
* \return A const iterator to the first element of the given matrix expression
* according to its orientation.
*/
template <typename TagT, typename ExprT>
BOOST_UBLAS_INLINE
typename const_iterator_type<ExprT,TagT>::type begin(matrix_expression<ExprT> const& e)
{
return detail::begin_impl<typename ExprT::type_category, TagT, typename ExprT::orientation_category>::apply(e());
}
/**
* \brief An iterator to the first element over the dual dimension of the given
* iterator.
* \tparam IteratorT A model of Iterator type.
* \param it An iterator.
* \return An iterator to the first element over the dual dimension of the given
* iterator.
*/
template <typename IteratorT>
BOOST_UBLAS_INLINE
typename IteratorT::dual_iterator_type begin(IteratorT& it)
{
return it.begin();
}
/**
* \brief A const iterator to the first element over the dual dimension of the
* given iterator.
* \tparam IteratorT A model of Iterator type.
* \param it An iterator.
* \return A const iterator to the first element over the dual dimension of the
* given iterator.
*/
template <typename IteratorT>
BOOST_UBLAS_INLINE
typename IteratorT::dual_iterator_type begin(IteratorT const& it)
{
return it.begin();
}
}}} // Namespace boost::numeric::ublas
#endif // BOOST_NUMERIC_UBLAS_OPERATION_BEGIN_HPP