xoptional_assembly_base¶
Defined in xtensor/xoptional_assembly_base.hpp
-
template<class D>
class xoptional_assembly_base : private xt::xiterable<D>¶ Base class for dense multidimensional optional assemblies.
The xoptional_assembly_base class defines the interface for dense multidimensional optional assembly classes. Optional assembly classes hold optional values and are optimized for tensor operations. xoptional_assembly_base does not embed any data container, this responsibility is delegated to the inheriting classes.
- Template Parameters
D – The derived type, i.e. the inheriting class for which xoptional_assembly_base provides the interface.
Size and shape
-
inline size_type size() const noexcept¶
Returns the number of element in the optional assembly.
-
inline constexpr size_type dimension() const noexcept¶
Returns the number of dimensions of the optional assembly.
-
inline const inner_shape_type &shape() const noexcept¶
Returns the shape of the optional assembly.
-
inline size_type shape(size_type index) const¶
Returns the i-th dimension of the expression.
-
inline const inner_strides_type &strides() const noexcept¶
Returns the strides of the optional assembly.
-
inline const inner_backstrides_type &backstrides() const noexcept¶
Returns the backstrides of the optional assembly.
Data
-
inline reference front()¶
Returns a reference to the first element of the optional assembly.
-
inline const_reference front() const¶
Returns a constant reference to the first element of the optional assembly.
-
inline reference back()¶
Returns a reference to the last element of the optional assembly.
-
inline const_reference back() const¶
Returns a constant reference to the last element of the optional assembly.
-
inline reference flat(size_type args)¶
Returns a reference to the element at the specified position of the underlying storage in the optional assembly.
- Parameters
index – index to underlying flat storage.
-
inline const_reference flat(size_type args) const¶
Returns a constant reference to the element at the specified position of the underlying storage in the optional assembly.
- Parameters
index – index to underlying flat storage.
-
template<class ...Args>
inline bool in_bounds(Args... args) const¶ Returns
true
only if the the specified position is a valid entry in the expression.- Parameters
args – a list of indices specifying the position in the expression.
- Returns
bool
-
template<class ...Args>
inline auto operator()(Args... args) -> reference¶ Returns a reference to the element at the specified position in the optional assembly.
- Parameters
args – a list of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices should be equal or greater than the number of dimensions of the optional assembly.
-
template<class ...Args>
inline auto operator()(Args... args) const -> const_reference¶ Returns a constant reference to the element at the specified position in the optional assembly.
- Parameters
args – a list of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices should be equal or greater than the number of dimensions of the optional assembly.
-
template<class ...Args>
inline auto at(Args... args) -> reference¶ Returns a reference to the element at the specified position in the optional assembly, after dimension and bounds checking.
- Parameters
args – a list of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices should be equal to the number of dimensions of the optional assembly.
- Throws
std::out_of_range – if the number of argument is greater than the number of dimensions or if indices are out of bounds.
-
template<class ...Args>
inline auto at(Args... args) const -> const_reference¶ Returns a constant reference to the element at the specified position in the optional assembly, after dimension and bounds checking.
- Parameters
args – a list of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices should be equal to the number of dimensions of the optional assembly.
- Throws
std::out_of_range – if the number of argument is greater than the number of dimensions or if indices are out of bounds.
-
template<class ...Args>
inline auto unchecked(Args... args) -> reference¶ Returns a reference to the element at the specified position in the optional assembly.
Warning
This method is meant for performance, for expressions with a dynamic number of dimensions (i.e. not known at compile time). Since it may have undefined behavior (see parameters), operator() should be prefered whenever it is possible.
Warning
This method is NOT compatible with broadcasting, meaning the following code has undefined behavior:
xt::xarray<double> a = {{0, 1}, {2, 3}}; xt::xarray<double> b = {0, 1}; auto fd = a + b; double res = fd.uncheked(0, 1);
- Parameters
args – a list of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices must be equal to the number of dimensions of the optional assembly, else the behavior is undefined.
-
template<class ...Args>
inline auto unchecked(Args... args) const -> const_reference¶ Returns a constant reference to the element at the specified position in the optional assembly.
Warning
This method is meant for performance, for expressions with a dynamic number of dimensions (i.e. not known at compile time). Since it may have undefined behavior (see parameters), operator() should be prefered whenever it is possible.
Warning
This method is NOT compatible with broadcasting, meaning the following code has undefined behavior:
xt::xarray<double> a = {{0, 1}, {2, 3}}; xt::xarray<double> b = {0, 1}; auto fd = a + b; double res = fd.uncheked(0, 1);
- Parameters
args – a list of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices must be equal to the number of dimensions of the optional assembly, else the behavior is undefined.
-
template<class S>
inline auto operator[](const S &index) -> disable_integral_t<S, reference>¶ Returns a reference to the element at the specified position in the optional assembly.
- Parameters
index – a sequence of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices in the list should be equal or greater than the number of dimensions of the optional assembly.
-
template<class S>
inline auto operator[](const S &index) const -> disable_integral_t<S, const_reference>¶ Returns a constant reference to the element at the specified position in the optional assembly.
- Parameters
index – a sequence of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices in the list should be equal or greater than the number of dimensions of the optional assembly.
-
template<class ...Args>
inline auto periodic(Args... args) -> reference¶ Returns a reference to the element at the specified position in the optional assembly, after applying periodicity to the indices (negative and ‘overflowing’ indices are changed).
- Parameters
args – a list of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices should be equal to the number of dimensions of the optional assembly.
-
template<class ...Args>
inline auto periodic(Args... args) const -> const_reference¶ Returns a constant reference to the element at the specified position in the optional assembly, after applying periodicity to the indices (negative and ‘overflowing’ indices are changed).
- Parameters
args – a list of indices specifying the position in the optional assembly. Indices must be unsigned integers, the number of indices should be equal to the number of dimensions of the optional assembly.
-
template<class It>
inline auto element(It first, It last) -> reference¶ Returns a reference to the element at the specified position in the optional assembly.
- Parameters
first – iterator starting the sequence of indices
last – iterator ending the sequence of indices The number of indices in the sequence should be equal to or greater than the number of dimensions of the optional assembly.
-
template<class It>
inline auto element(It first, It last) const -> const_reference¶ Returns a constant reference to the element at the specified position in the optional assembly.
- Parameters
first – iterator starting the sequence of indices
last – iterator ending the sequence of indices The number of indices in the sequence should be equal to or greater than the number of dimensions of the optional assembly.
Broadcasting
-
template<class S>
inline bool broadcast_shape(S &shape, bool reuse_cache = false) const¶ Broadcast the shape of the optional assembly to the specified parameter.
- Parameters
shape – the result shape
reuse_cache – parameter for internal optimization
- Returns
a boolean indicating whether the broadcasting is trivial
-
template<class S>
inline bool has_linear_assign(const S &strides) const noexcept¶ Checks whether the xoptional_assembly_base can be linearly assigned to an expression with the specified strides.
- Returns
a boolean indicating whether a linear assign is possible
Public Functions
-
template<class S = shape_type>
inline void resize(const S &shape, bool force = false)¶ Resizes the optional assembly.
- Parameters
shape – the new shape
force – force reshaping, even if the shape stays the same (default: false)
-
template<class S = shape_type>
inline void resize(const S &shape, layout_type l)¶ Resizes the optional assembly.
- Parameters
shape – the new shape
l – the new layout_type
-
template<class S = shape_type>
inline void resize(const S &shape, const strides_type &strides)¶ Resizes the optional assembly.
- Parameters
shape – the new shape
strides – the new strides
-
inline layout_type layout() const noexcept¶
Return the layout_type of the container.
- Returns
layout_type of the container
-
template<class T>
inline void fill(const T &value)¶ Fills the data with the given value.
- Parameters
value – the value to fill the data with.
-
inline value_expression value() noexcept¶
Return an expression for the values of the optional assembly.
-
inline const_value_expression value() const noexcept¶
Return a constant expression for the values of the optional assembly.
-
inline flag_expression has_value() noexcept¶
Return an expression for the missing mask of the optional assembly.
-
inline const_flag_expression has_value() const noexcept¶
Return a constant expression for the missing mask of the optional assembly.
-
template<class S>
inline auto &reshape(const S &shape, layout_type layout) &¶ Reshapes the optional assembly.
- Parameters
shape – the new shape
layout – the new layout