Strides

basic_strides<size_type, format_type>

Description

The template class basic_strides contains weights for a given storage format in order to map multi-indices to scalar memory indices for tensor instances.

Example

#include <boost/numeric/ublas/tensor/strides.hpp>

int main () {
    using namespace boost::numeric::ublas;
    auto wf = strides<first_order>(shape{4,3,2});
    for (auto i = 0u; i < wf.size(); ++i)
        std::cout << wf.at(i) << std::endl;
        // 1,4,12

    auto wl = strides<first_order>(shape{4,3,2});
    for (auto i = 0u; i < wl.size(); ++i)
        std::cout << wl.at(i) << std::endl;
        // 6,2,1
}

Definition

Defined in the header tensor/strides.hpp.

Public base classes

None.

Specialization

template<class format_t>using strides = basic_strides<std::size_t,format_t>

Template parameters

Parameter

Description

size_type

Unsigned integer type.

Member types

Member type Description

Member type	Description
`value_type`	Type `size_type` of the strides.
`size_type`	Unsigned integer such as `std::size_t`.
`reference`	Reference type which is `value_type&`.
`const_reference`	Constant reference type which is `const value_type&`.
`pointer`	Pointer type which is `value_type*`.
`const_pointer`	Constant pointer type which is `const value_type*`.
`layout_type`	Layout type which can be either `boost::numeric::ublas::first_order` or `boost::numeric::ublas::last_order`.

value_type

Type size_type of the strides.

size_type

Unsigned integer such as std::size_t.

reference

Reference type which is value_type&.

const_reference

Constant reference type which is const value_type&.

pointer

Pointer type which is value_type*.

const_pointer

Constant pointer type which is const value_type*.

layout_type

Layout type which can be either boost::numeric::ublas::first_order or boost::numeric::ublas::last_order.

Member Functions

Member Function Description

Member Function	Description
`basic_strides ()`	Constructs an empty instance of `basic_strides`.
`basic_strides (basic_extents<value_type> const& be)`	Constructs an instance based on the tensor extents specified by `be`.
`basic_strides (std::vector<value_type> const& v)`	Constructs an instance copying the content of `v`.
`basic_strides (std::vector<value_type> && v)`	Constructs an instance moving the content of `v`.
`basic_strides (basic_strides const& other)`	Constructs an instance from `other` copying its elements.
`basic_strides (basic_strides && other)`	Constructs an instance from `other` by moving its elements.
`basic_strides& operator= (basic_strides other)`	Assigns the elements of `other` to this instance.
`const_pointer data() const`	Returns a `const_pointer` to the first element.
`const_reference operator[](size_type i) const`	Returns a `const_reference` to the `i`-th element.
`const_reference at(size_type i) const`	Returns a `const_reference` to the `i`-th element.
`bool empty()`	Returns true if the container has no elements.
`size_type size() const`	Returns the number of elements.
`void clear()`	Erases all elements.
`bool operator==(basic_strides const& b) const`	Returns true if all elements are equal.
`bool operator!=(basic_strides const& b) const`	Returns true if some elements are not equal.
`const_iterator begin() const`	Returns an `const_iterator` pointing to the first element.
`const_iterator end() const`	Returns a `const_iterator` pointing to an element passed the last element.
`std::vector<size_type> base() const`	Returns the private member sequence container holding all elements.

basic_strides ()

Constructs an empty instance of basic_strides.

basic_strides (basic_extents<value_type> const& be)

Constructs an instance based on the tensor extents specified by be.

basic_strides (std::vector<value_type> const& v)

Constructs an instance copying the content of v.

basic_strides (std::vector<value_type> && v)

Constructs an instance moving the content of v.

basic_strides (basic_strides const& other)

Constructs an instance from other copying its elements.

basic_strides (basic_strides && other)

Constructs an instance from other by moving its elements.

basic_strides& operator= (basic_strides other)

Assigns the elements of other to this instance.

const_pointer data() const

Returns a const_pointer to the first element.

const_reference operator[](size_type i) const

Returns a const_reference to the i-th element.

const_reference at(size_type i) const

Returns a const_reference to the i-th element.

bool empty()

Returns true if the container has no elements.

size_type size() const

Returns the number of elements.

void clear()

Erases all elements.

bool operator==(basic_strides const& b) const

Returns true if all elements are equal.

bool operator!=(basic_strides const& b) const

Returns true if some elements are not equal.

const_iterator begin() const

Returns an const_iterator pointing to the first element.

const_iterator end() const

Returns a const_iterator pointing to an element passed the last element.

std::vector<size_type> base() const

Returns the private member sequence container holding all elements.

Non-Member Functions

Function Description

Function	Description
`access(std::vector<size_type> const& i, strides<layout_type> w)`	Returns relative memory location depending on the multi-index vector `i` and strides `w`.
`access(size_type sum, strides<layout_type> w, size_type i, size_types … is)`	Returns relative memory location depending on the indices `i`, `is …` and stride vector `w` (recursive function).

access(std::vector<size_type> const& i, strides<layout_type> w)

Returns relative memory location depending on the multi-index vector i and strides w.

access(size_type sum, strides<layout_type> w, size_type i, size_types … is)

Returns relative memory location depending on the indices i, is … and stride vector w (recursive function).

Copyright (©) 2018 Cem Bassoy
Copyright (©) 2021 Shikhar Vashistha
Use, modification and distribution are subject to 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 ).