diff options
author | Gael Guennebaud <g.gael@free.fr> | 2017-01-11 17:24:02 +0100 |
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committer | Gael Guennebaud <g.gael@free.fr> | 2017-01-11 17:24:02 +0100 |
commit | 752bd92ba53de344eba66b8cec4480f9d3207025 (patch) | |
tree | 5f1fd07a73cfd143233351313838a71f026fef12 /Eigen/src/Core/util/IndexedViewHelper.h | |
parent | f93d1c58e09b8435191a55f123873d8f496620b6 (diff) |
Large code refactoring:
- generalize some utilities and move them to Meta (size(), array_size())
- move handling of all and single indices to IndexedViewHelper.h
- several cleanup changes
Diffstat (limited to 'Eigen/src/Core/util/IndexedViewHelper.h')
-rw-r--r-- | Eigen/src/Core/util/IndexedViewHelper.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/Eigen/src/Core/util/IndexedViewHelper.h b/Eigen/src/Core/util/IndexedViewHelper.h new file mode 100644 index 000000000..4f6dd065e --- /dev/null +++ b/Eigen/src/Core/util/IndexedViewHelper.h @@ -0,0 +1,111 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2017 Gael Guennebaud <gael.guennebaud@inria.fr> +// +// This Source Code Form is subject to the terms of the Mozilla +// Public License v. 2.0. If a copy of the MPL was not distributed +// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. + + +#ifndef EIGEN_INDEXED_VIEW_HELPER_H +#define EIGEN_INDEXED_VIEW_HELPER_H + +namespace Eigen { + +namespace internal { + +// Extract increment/step at compile time +template<typename T, typename EnableIf = void> struct get_compile_time_incr { + enum { value = UndefinedIncr }; +}; + +// Analogue of std::get<0>(x), but tailored for our needs. +template<typename T> +Index first(const T& x) { return x.first(); } + +// IndexedViewCompatibleType/makeIndexedViewCompatible turn an arbitrary object of type T into something usable by MatrixSlice +// The generic implementation is a no-op +template<typename T,int XprSize,typename EnableIf=void> +struct IndexedViewCompatibleType { + typedef T type; +}; + +template<typename T> +const T& makeIndexedViewCompatible(const T& x, Index /*size*/) { return x; } + +//-------------------------------------------------------------------------------- +// Handling of a single Index +//-------------------------------------------------------------------------------- + +struct SingleRange { + enum { + SizeAtCompileTime = 1 + }; + SingleRange(Index val) : m_value(val) {} + Index operator[](Index) const { return m_value; } + Index size() const { return 1; } + Index first() const { return m_value; } + Index m_value; +}; + +template<> struct get_compile_time_incr<SingleRange> { + enum { value = 1 }; // 1 or 0 ?? +}; + +// Turn a single index into something that looks like an array (i.e., that exposes a .size(), and operatro[](int) methods) +template<typename T, int XprSize> +struct IndexedViewCompatibleType<T,XprSize,typename internal::enable_if<internal::is_integral<T>::value>::type> { + // Here we could simply use Array, but maybe it's less work for the compiler to use + // a simpler wrapper as SingleRange + //typedef Eigen::Array<Index,1,1> type; + typedef SingleRange type; +}; + +//-------------------------------------------------------------------------------- +// Handling of all +//-------------------------------------------------------------------------------- + +struct all_t { all_t() {} }; + +// Convert a symbolic 'all' into a usable range type +template<int XprSize> +struct AllRange { + enum { SizeAtCompileTime = XprSize }; + AllRange(Index size = XprSize) : m_size(size) {} + Index operator[](Index i) const { return i; } + Index size() const { return m_size.value(); } + Index first() const { return 0; } + variable_if_dynamic<Index,XprSize> m_size; +}; + +template<int XprSize> +struct IndexedViewCompatibleType<all_t,XprSize> { + typedef AllRange<XprSize> type; +}; + +template<typename XprSizeType> +inline AllRange<get_compile_time<XprSizeType>::value> makeIndexedViewCompatible(all_t , XprSizeType size) { + return AllRange<get_compile_time<XprSizeType>::value>(size); +} + +template<int Size> struct get_compile_time_incr<AllRange<Size> > { + enum { value = 1 }; +}; + +} // end namespace internal + + +namespace placeholders { + +/** \var all + * \ingroup Core_Module + * Can be used as a parameter to DenseBase::operator()(const RowIndices&, const ColIndices&) to index all rows or columns + */ +static const Eigen::internal::all_t all; + +} + +} // end namespace Eigen + +#endif // EIGEN_INDEXED_VIEW_HELPER_H |