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A first general restructuration of the doc according to the pattern [tour|tutorial|reference]. In the reference part, objects are documented per topic. In each topic, [definition|c++|python|hdf5] (not yet implemented)
255 lines
17 KiB
ReStructuredText
255 lines
17 KiB
ReStructuredText
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.. _impl_concepts:
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Concepts
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=============================================================
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BoostSerializable
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-------------------------------------------------
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* define serialize for boost serialize library
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Printable
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-------------------------------------------------
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====================================================== ===========================================================
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Elements Comment
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====================================================== ===========================================================
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std::ostream & operator << (std::ostream & out, ...) Printing
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====================================================== ===========================================================
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Domain
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-------------------------------------------------
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* **Purpose** : The domain of definition of the array, i.e. the possible value of the indices.
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* **Refines**: BoostSerializable, Printable
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* **Definition**:
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+------------------------------------------------------------------+-------------------------------------------------------+
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| Elements | Comment |
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+==================================================================+=======================================================+
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| static const unsigned int rank | rank |
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+------------------------------------------------------------------+-------------------------------------------------------+
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| index_value_type | type of the multi-index |
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+------------------------------------------------------------------+-------------------------------------------------------+
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| default constructor, copy construction | |
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+------------------------------------------------------------------+-------------------------------------------------------+
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| operator = | |
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+------------------------------------------------------------------+-------------------------------------------------------+
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| operator ==, != | |
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+------------------------------------------------------------------+-------------------------------------------------------+
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| size_t number_of_elements() const | number of elements |
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+------------------------------------------------------------------+-------------------------------------------------------+
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| generator | type of the IndexGenerator that generates the indices |
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+------------------------------------------------------------------+-------------------------------------------------------+
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| begin() const/ end() const | a generator at start/end |
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+------------------------------------------------------------------+-------------------------------------------------------+
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* **Examples** :
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Typically, this is is a multi-index for an array, matrix, ...., e.g.
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* Cuboid<rank>: standard hyperrectangular arrays. This is little more than the tuple of the lengths.
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* triangle, .... ?
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.. _HasImmutableArrayInterface:
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HasImmutableArrayInterface
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-------------------------------------------------
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* **Purpose**: The most abstract definition of something that behaves like an immutable array.
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* it has a domain (hence a rank).
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* it can be evaluated on any value of the indices in the domain
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* By combining the generator of the domain with the evaluation, it is therefore easy to
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iterate on the values of such an object.
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* NB: It does not need to be stored in memory. A formal expression, e.g. model this concept.
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* **Definition** ([A|B] denotes that the return type maybe A or B).
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================================================================================================== =============================================================
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Elements Comment
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================================================================================================== =============================================================
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value_type Type of the element of the array
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domain_type Type of the domain.
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[domain_type const & | domain_type] domain() const Access to the domain.
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[ value_type | value_type const &] operator[] (domain_type::index_value_type const &) const Evaluation.
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================================================================================================== =============================================================
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* **Examples**:
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* array, array_view, matrix, matrix_view, vector, vector_view (all implemented as Indexmap_Storage_Pair)
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* array expressions (in which case the returns are not const & since they are computed, not stored).
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IndexGenerator
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-------------------------------------------------
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* **Purpose**: Generate the indices of a domain.
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* **Definition**:
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============================================================== ==================================================================================================
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Elements Comment
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============================================================== ==================================================================================================
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domain_type Type of the domain whose indices are generated.
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default contruction, copy construction
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construction from (domain_type const &, bool atend=false)
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IndexGenerator & operator=(const IndexGenerator & )
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operator ++
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operator =
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operator ==, !=
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domain_type::index_value_type const & operator * () const Access to the value of the multi-index
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bool at_end() const True iif the generator has reached the last value
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============================================================== ==================================================================================================
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* **Examples** :
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* cuboid_index_generator
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IndexMap
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-------------------------------------------------
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* **Purpose**:
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* Store the mapping of the index domain to a linear array.
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* It is basically a function: indices --> 1d position, the bijection between the indices
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of an element and its position in the memory block.
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* **Refines**: BoostSerializable, Printable
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* **Definition**:
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======================================================================== ==================================================================================================
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Elements Comment
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======================================================================== ==================================================================================================
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* domain_type The type of the domain.
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* domain_type const & domain() const The domain.
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* default constructor, copy construction Cpy is a true copy.
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* can be constructed from domain_type const &
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* size_t operator[] (domain_type::index_value_type const & key ) const The mapping itself.
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* iterator A type modeling IndexMapIterator, which is the optimal memory traversal.
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NB: the order of indices is chosen for optimal traversal of memory, it
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does not need to be "natural".
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cuboid_map also provides a natural_iterator for that purpose.
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======================================================================== ==================================================================================================
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* The type also has to define two free functions and to specialize a template:
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========================================================== ==================================================================================================
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Elements Comment
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========================================================== ==================================================================================================
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* bool compatible_for_assignment (M1, M2) Returns whether an array/matrix/vector with map M1 can be equated to a array/matrix/vector with
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map M2
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* bool raw_copy_possible (M1, M2) Is the assignment of an array/matrix/vector with map M2 into an array/matrix/vector with map M1
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doable with raw copy
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* struct indexmap_iterator_adapter< It, I > Metafunction:
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- I is the IndexMap class
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- It any similar IndexMapIterator which returns (in ::type) the IndexMapIterator on I
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with the same order traversal as It.
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Example: It is a IndexMapIterator on I1 stored in C order, I is in Fortran order,
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the result will be an IndexMapIterator on I that presents the data of I in C order
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This is used in copying array with different indexmaps.
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========================================================== ==================================================================================================
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* **Examples**:
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* cuboid_map<IterationOrder> : a map of the cuboid indices in a fixed order in memory.
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IndexMapIterator
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-------------------------------------------------
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* **Purpose**:
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* A basic iterator on an IndexMap which can be dereferenced into the shift of successive elements compared to the start of the memory block.
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* These iterators are kept as simple as possible, so that it is easy to implement new indices maps and their iterators.
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* NB: In particular, they are *not* necessary STL-compliant. The array_iterator class will
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take such an iterator and a Storage and produce a true, STL compliant iterator on the array (iterator_adapter).
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* **Definition**:
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========================================================== ==================================================================================================
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Elements Comment
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========================================================== ==================================================================================================
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indexmap_type The index_map on which the iterator is iterating
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domain_type Type of the domain whose indices are generated.
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default contruction, copy construction
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construction from (domain_type const &, bool atend=false)
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IndexMapIterator & operator=(const IndexMapIterator & )
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IndexMapIterator & operator ++
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operator ==, !=
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std::ptrdiff_t operator*() const Dereference as a shift from the beginning of the array
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domain_type::index_value_type const & indices () const Access to the value of the multi-index at the iterator position
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bool at_end() const True iif the generator has reached the last value (in practice quicker that it = XX.end()).
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========================================================== ==================================================================================================
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* **Example(s)** :
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* cuboid_map_iterator
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Storage
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-------------------------------------------------
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* **Purpose**:
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* The storage of the array in memory, e.g. plain C++ array, a numpy, etc...
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* A Storage keeps the reference to the memory block where the array is stored.
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* NB: This memory block can be typically shared between various arrays and views,
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so the Storage is just a reference. The memory is deallocated only
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when all storages referencing it has been destroyed.
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* **Refines**: BoostSerializable
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* **Definition** :
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====================================================== ==================================================================================================
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Elements Comment
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====================================================== ==================================================================================================
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value_type Type of the element stored, e.g. int, const int, double, const double, ...
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default construction Makes a storage of size 0
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copy construction a shallow copy (another reference to the same data).
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the copy construction is possible from another storage of the same value_type
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up to the const qualifier.
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The construction of a storage with value_type=T from a storage with value_type const T
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is forbidden at compile time.
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void operator = (const STO &) A shallow copy of the reference to the data.
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clone() const Create a clone of the data.
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const_clone() const Create a clone of the data with const value_type (e.g. int--> const int).
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void raw_copy_from(const STO & X) Copy all the data from X to * this. Behaviour undefined if sizes do not match.
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size_t size() const Number of elements in the storage
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value_type & operator[](size_t p) const Access to the data. Behaviour is undefined if empty()==true.
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====================================================== ==================================================================================================
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StorageOrder concept
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-------------------------------------------------
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* **Purpose** :
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* Store the order of indices in memory.
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* Can be fixed at compile time, or dynamically (not implemented).
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* **Refines**: BoostSerializable
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* **Definition** :
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====================================================== ==================================================================================================
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Elements Comment
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====================================================== ==================================================================================================
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size_t index_number(size_t i)
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static unsigned int rank
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default construction
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copy construction
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bool is_Fortran() const Is it Fortran-style ordering ?
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bool is_C() const Is it C-style ordering ?
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====================================================== ==================================================================================================
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* The type also has to define the == operator:
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========================================================== ==================================================================================================
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Elements Comment
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========================================================== ==================================================================================================
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Operator == Defined between any of the ordering.
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========================================================== ==================================================================================================
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