lines 8-101 of file: include/cppad/core/atomic/two/ctor.hpp

{xrst_begin atomic_two_ctor app}

Atomic Function Constructor
###########################

Syntax
******

| *atomic_user afun* ( *ctor_arg_list* )
| ``atomic_base`` < *Base* >( *name* , *sparsity* )

atomic_user
***********

ctor_arg_list
=============
Is a list of arguments for the *atomic_user* constructor.

afun
====
The object *afun* must stay in scope for as long
as the corresponding atomic function is used.
This includes use by any :ref:`ADFun\<Base><ADFun-name>` that
has this *atomic_user* operation in its
:ref:`operation sequence<glossary@Operation@Sequence>` .

Implementation
==============
The user defined *atomic_user* class is a publicly derived class of
``atomic_base`` < *Base* > .
It should be declared as follows:

| |tab| ``class`` *atomic_user* : ``public CppAD::atomic_base<`` *Base* > {
| |tab| ``public:``
| |tab| |tab| *atomic_user* ( *ctor_arg_list* ) : ``atomic_base`` < *Base* >( *name* , *sparsity* )
| |tab| ...
| |tab| };

where ...
denotes the rest of the implementation of the derived class.
This includes completing the constructor and
all the virtual functions that have their
``atomic_base`` implementations replaced by
*atomic_user* implementations.

atomic_base
***********

Restrictions
============
The ``atomic_base`` constructor and destructor cannot be called in
:ref:`parallel<ta_in_parallel-name>` mode.

Base
====
The template parameter determines the
*Base* type for this ``AD`` < *Base* > atomic operation.

name
====
This ``atomic_base`` constructor argument has the following prototype

   ``const std::string&`` *name*

It is the name for this atomic function and is used for error reporting.
The suggested value for *name* is *afun* or *atomic_user* ,
i.e., the name of the corresponding atomic object or class.

sparsity
========
This ``atomic_base`` constructor argument has prototype

   ``atomic_base`` < *Base* >:: ``option_enum`` *sparsity*

The current *sparsity* for an ``atomic_base`` object
determines which type of sparsity patterns it uses
and its value is one of the following:

.. list-table::
   :widths: auto

   * - *sparsity*
     - sparsity patterns
   * - ``atomic_base`` < *Base* >:: ``pack_sparsity_enum``
     - :ref:`CppAD_vector@vectorBool`
   * - ``atomic_base`` < *Base* >:: ``bool_sparsity_enum``
     - :ref:`vector<CppAD_vector-name>` ``<bool>``
   * - ``atomic_base`` < *Base* >:: ``set_sparsity_enum``
     - :ref:`vector<CppAD_vector-name>` ``<std::set<std::size_t> >``

There is a default value for *sparsity* if it is not
included in the constructor (which may be either the bool or set option).

{xrst_end atomic_two_ctor}