Classes
class	IteratorRange< Iterator >

Functions
template<typename FunctionObjectType >
auto	Threads::new_thread (FunctionObjectType function_object) -> Thread< decltype(function_object())>

template<typename FunctionObjectType >
auto	Threads::new_task (FunctionObjectType function_object) -> Task< decltype(function_object())>

template<typename BaseIterator , typename Predicate >
IteratorRange< FilteredIterator< BaseIterator > >	filter_iterators (IteratorRange< BaseIterator > i, const Predicate &p)

template<typename BaseIterator , typename Predicate , typename... Targs>
IteratorRange< typename internal::FilteredIteratorImplementation::NestFilteredIterators< BaseIterator, std::tuple< Predicate, Targs... > >::type >	filter_iterators (IteratorRange< BaseIterator > i, const Predicate &p, const Targs... args)

template<typename BaseIterator , typename Predicate >
IteratorRange< FilteredIterator< BaseIterator > >	filter_iterators (IteratorRange< BaseIterator > i, const Predicate &p)

template<typename BaseIterator , typename Predicate , typename... Targs>
IteratorRange< typename internal::FilteredIteratorImplementation::NestFilteredIterators< BaseIterator, std::tuple< Predicate, Targs... > >::type >	filter_iterators (IteratorRange< BaseIterator > i, const Predicate &p, const Targs... args)

Cell iterator functions returning ranges of iterators
IteratorRange< cell_iterator >	DoFHandler< dim, spacedim >::cell_iterators () const

IteratorRange< active_cell_iterator >	DoFHandler< dim, spacedim >::active_cell_iterators () const

IteratorRange< level_cell_iterator >	DoFHandler< dim, spacedim >::mg_cell_iterators () const

IteratorRange< cell_iterator >	DoFHandler< dim, spacedim >::cell_iterators_on_level (const unsigned int level) const

IteratorRange< active_cell_iterator >	DoFHandler< dim, spacedim >::active_cell_iterators_on_level (const unsigned int level) const

IteratorRange< level_cell_iterator >	DoFHandler< dim, spacedim >::mg_cell_iterators_on_level (const unsigned int level) const

Cell iterator functions returning ranges of iterators
IteratorRange< cell_iterator >	Triangulation< dim, spacedim >::cell_iterators () const

IteratorRange< active_cell_iterator >	Triangulation< dim, spacedim >::active_cell_iterators () const

IteratorRange< cell_iterator >	Triangulation< dim, spacedim >::cell_iterators_on_level (const unsigned int level) const

IteratorRange< active_cell_iterator >	Triangulation< dim, spacedim >::active_cell_iterators_on_level (const unsigned int level) const

Cell iterator functions returning ranges of iterators
IteratorRange< cell_iterator >	hp::DoFHandler< dim, spacedim >::cell_iterators () const

IteratorRange< active_cell_iterator >	hp::DoFHandler< dim, spacedim >::active_cell_iterators () const

IteratorRange< cell_iterator >	hp::DoFHandler< dim, spacedim >::cell_iterators_on_level (const unsigned int level) const

IteratorRange< active_cell_iterator >	hp::DoFHandler< dim, spacedim >::active_cell_iterators_on_level (const unsigned int level) const

Detailed Description

Since version 9.0, deal.II requires a compiler that supports at least C++11. As part of this, many places in the internal implementation of deal.II are now using features that were only introduced in C++11. That said, deal.II also has functions and classes that make using it with C++11 features easier.

One example is support for C++11 range-based for loops. deal.II-based codes often have many loops of the kind

Triangulation<dim> triangulation;
...
typename Triangulation<dim>::active_cell_iterator
  cell = triangulation.begin_active(),
  endc = triangulation.end();
for (; cell!=endc; ++cell)
  cell->set_refine_flag();

Using C++11's range-based for loops, you can now write this as follows:

Triangulation<dim> triangulation;
...
for (auto cell : triangulation.active_cell_iterators())
  cell->set_refine_flag();

This relies on functions such as Triangulation::active_cell_iterators(), and equivalents in the DoF handler classes, DoFHandler::active_cell_iterators(), hp::DoFHandler::active_cell_iterators(). There are variants of these functions that provide iterator ranges for all cells (not just the active ones) and for cells on individual levels.

Function Documentation

◆ new_thread()

template<typename FunctionObjectType >

auto Threads::new_thread ( FunctionObjectType function_object ) -> Thread<decltype(function_object())>

inline

Overload of the new_thread() function for objects that can be called like a function object without arguments. In particular, this function allows calling Threads::new_thread() with either objects that result from using std::bind, or using lambda functions. For example, this function is called when writing code such as

Threads::Thread<int>
  thread = Threads::new_thread ( [] () {
                                         do_this();
                                         then_do_that();
                                         return 42;
                                       });

Here, we run the sequence of functions do_this() and then_do_that() on a separate thread, by making the lambda function declared here the function to execute on the thread. The lambda function then returns 42 (which is a bit pointless here, but it could of course be some computed number), and this is going to be the returned value you can later retrieve via thread.return_value() once the thread (i.e., the body of the lambda function) has completed.

Note: Every lambda function (or whatever else it is you pass to the new_thread() function here, for example the result of a std::bind() expression) has a return type and consequently returns an object of this type. This type can be inferred using the C++11 decltype statement used in the declaration of this function, and it is then used as the template argument of the Threads::Thread object returned by the current function. In the example above, because the lambda function returns 42 (which in C++ has data type int), the inferred type is int and the task object will have type Task<int>. In other words, it is not necessary to explicitly specify in user code what that return type of the lambda or std::bind expression will be, though it is possible to explicitly do so by (entirely equivalently) writing
Threads::Thread<int>
thread = Threads::new_thread ( [] () -> int {
do_this();
then_do_that();
return 42;
});; In practice, the lambda functions you will pass to new_thread() will of course typically be more complicated. In particular, they will likely capture variables from the surrounding context and use them within the lambda. See https://en.wikipedia.org/wiki/Anonymous_function#C.2B.2B_.28since_C.2B.2B11.29 for more on how lambda functions work.; If you pass a lambda function as an argument to the current function that captures a variable by reference, or if you use a std::bind that binds a function argument to a reference variable using std::ref() or std::cref(), then obviously you can only do this if the variables you reference or capture have a lifetime that extends at least until the time where the thread finishes.

Definition at line 1236 of file thread_management.h.

◆ new_task()

template<typename FunctionObjectType >

auto Threads::new_task ( FunctionObjectType function_object ) -> Task<decltype(function_object())>

inline

Overload of the new_task function for objects that can be called like a function object without arguments. In particular, this function allows calling Threads::new_task() with either objects that result from using std::bind, or using lambda functions. For example, this function is called when writing code such as

Threads::Task<int>
  task = Threads::new_task ( [] () {
                                     do_this();
                                     then_do_that();
                                     return 42;
                                   });

Here, we schedule the call to the sequence of functions do_this() and then_do_that() on a separate task, by making the lambda function declared here the function to execute on the task. The lambda function then returns 42 (which is a bit pointless here, but it could of course be some computed number), and this is going to be the returned value you can later retrieve via task.return_value() once the task (i.e., the body of the lambda function) has completed.

Note: Every lambda function (or whatever else it is you pass to the new_task() function here, for example the result of a std::bind() expression) has a return type and consequently returns an object of this type. This type can be inferred using the C++11 decltype statement used in the declaration of this function, and it is then used as the template argument of the Threads::Task object returned by the current function. In the example above, because the lambda function returns 42 (which in C++ has data type int), the inferred type is int and the task object will have type Task<int>. In other words, it is not necessary to explicitly specify in user code what that return type of the lambda or std::bind expression will be, though it is possible to explicitly do so by (entirely equivalently) writing
Threads::Task<int>
task = Threads::new_task ( [] () -> int {
do_this();
then_do_that();
return 42;
});; In practice, the lambda functions you will pass to new_task() will of course typically be more complicated. In particular, they will likely capture variables from the surrounding context and use them within the lambda. See https://en.wikipedia.org/wiki/Anonymous_function#C.2B.2B_.28since_C.2B.2B11.29 for more on how lambda functions work.; If you pass a lambda function as an argument to the current function that captures a variable by reference, or if you use a std::bind that binds a function argument to a reference variable using std::ref() or std::cref(), then obviously you can only do this if the variables you reference or capture have a lifetime that extends at least until the time where the task finishes.

Definition at line 1911 of file thread_management.h.

◆ cell_iterators() [1/3]

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::cell_iterator > DoFHandler< dim, spacedim >::cell_iterators ( ) const

Return an iterator range that contains all cells (active or not) that make up this DoFHandler. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Returns: The half open range [this->begin(), this->end())

Definition at line 820 of file dof_handler.cc.

◆ active_cell_iterators() [1/3]

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::active_cell_iterator > DoFHandler< dim, spacedim >::active_cell_iterators ( ) const

Return an iterator range that contains all active cells that make up this DoFHandler. Such a range is useful to initialize range-based for loops as supported by C++11, see also C++11 standard.

Range-based for loops are useful in that they require much less code than traditional loops (see here for a discussion of how they work). An example is that without range-based for loops, one often writes code such as the following:

DoFHandler<dim> dof_handler;
...
typename DoFHandler<dim>::active_cell_iterator
  cell = dof_handler.begin_active(),
  endc = dof_handler.end();
for (; cell!=endc; ++cell)
  {
    fe_values.reinit (cell);
    ...do the local integration on 'cell'...;
  }

Using C++11's range-based for loops, this is now entirely equivalent to the following:

DoFHandler<dim> dof_handler;
...
for (auto cell : dof_handler.active_cell_iterators())
  {
    fe_values.reinit (cell);
    ...do the local integration on 'cell'...;
  }

Returns: The half open range [this->begin_active(), this->end())

Definition at line 830 of file dof_handler.cc.

◆ mg_cell_iterators()

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::level_cell_iterator > DoFHandler< dim, spacedim >::mg_cell_iterators ( ) const

Return an iterator range that contains all cells (active or not) that make up this DoFHandler in their level-cell form. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Returns: The half open range [this->begin_mg(), this->end_mg())

Definition at line 841 of file dof_handler.cc.

◆ cell_iterators_on_level() [1/3]

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::cell_iterator > DoFHandler< dim, spacedim >::cell_iterators_on_level ( const unsigned int level ) const

Return an iterator range that contains all cells (active or not) that make up the given level of this DoFHandler. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Parameters

[in] level A given level in the refinement hierarchy of this triangulation.

Returns: The half open range [this->begin(level), this->end(level))

Precondition: level must be less than this->n_levels().

Definition at line 853 of file dof_handler.cc.

◆ active_cell_iterators_on_level() [1/3]

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::active_cell_iterator > DoFHandler< dim, spacedim >::active_cell_iterators_on_level ( const unsigned int level ) const

Return an iterator range that contains all active cells that make up the given level of this DoFHandler. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Parameters

[in] level A given level in the refinement hierarchy of this triangulation.

Returns: The half open range [this->begin_active(level), this->end(level))

Precondition: level must be less than this->n_levels().

Definition at line 864 of file dof_handler.cc.

◆ mg_cell_iterators_on_level()

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::level_cell_iterator > DoFHandler< dim, spacedim >::mg_cell_iterators_on_level ( const unsigned int level ) const

Return an iterator range that contains all cells (active or not) that make up the given level of this DoFHandler in their level-cell form. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Parameters

[in] level A given level in the refinement hierarchy of this triangulation.

Returns: The half open range [this->begin_mg(level), this->end_mg(level))

Precondition: level must be less than this->n_levels().

Definition at line 875 of file dof_handler.cc.

◆ filter_iterators() [1/4]

template<typename BaseIterator , typename Predicate >

IteratorRange< FilteredIterator< BaseIterator > > filter_iterators	(	IteratorRange< BaseIterator >	i,
		const Predicate &	p
	)

Filter the given range of iterators using a Predicate. This allows to replace:

DoFHandler<dim> dof_handler;
...
for (auto cell : dof_handler.active_cell_iterators())
  {
    if (cell->is_locally_owned())
      {
        fe_values.reinit (cell);
        ...do the local integration on 'cell'...;
      }
  }

by:

DoFHandler<dim> dof_handler;
...
for (auto cell : filter_iterators(dof_handler.active_cell_iterators(),
                                 IteratorFilters::LocallyOwnedCell())
  {
    fe_values.reinit (cell);
    ...do the local integration on 'cell'...;
  }

Author: Bruno Turcksin, 2016

Definition at line 838 of file filtered_iterator.h.

◆ filter_iterators() [2/4]

template<typename BaseIterator , typename Predicate , typename... Targs>

IteratorRange< typename internal::FilteredIteratorImplementation::NestFilteredIterators< BaseIterator, std::tuple< Predicate, Targs... > >::type > filter_iterators	(	IteratorRange< BaseIterator >	i,
		const Predicate &	p,
		const Targs...	args
	)

Filter the given range of iterators through an arbitrary number of Predicates. This allows to replace:

DoFHandler<dim> dof_handler;
...
for (auto cell : dof_handler.active_cell_iterators())
  {
    if (cell->is_locally_owned())
      {
        if (cell->at_boundary())
          {
            fe_values.reinit (cell);
            ...do the local integration on 'cell'...;
          }
      }
  }

by:

DoFHandler<dim> dof_handler;
...
for (auto cell : filter_iterators(dof_handler.active_cell_iterators(),
                                 IteratorFilters::LocallyOwnedCell(),
                                 IteratorFilters::AtBoundary())
  {
    fe_values.reinit (cell);
    ...do the local integration on 'cell'...;
  }

Author: Bruno Turcksin, 2016

Definition at line 887 of file filtered_iterator.h.

◆ cell_iterators() [2/3]

template<int dim, int spacedim>

IteratorRange< typename Triangulation< dim, spacedim >::cell_iterator > Triangulation< dim, spacedim >::cell_iterators ( ) const

Return an iterator range that contains all cells (active or not) that make up this triangulation. Such a range is useful to initialize range- based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Returns: The half open range [this->begin(), this->end())

Definition at line 10622 of file tria.cc.

◆ active_cell_iterators() [2/3]

template<int dim, int spacedim>

IteratorRange< typename Triangulation< dim, spacedim >::active_cell_iterator > Triangulation< dim, spacedim >::active_cell_iterators ( ) const

Return an iterator range that contains all active cells that make up this triangulation. Such a range is useful to initialize range-based for loops as supported by C++11, see also C++11 standard.

Range-based for loops are useful in that they require much less code than traditional loops (see here for a discussion of how they work). An example is that without range-based for loops, one often writes code such as the following (assuming for a moment that our goal is setting the user flag on every active cell):

Triangulation<dim> triangulation;
...
typename Triangulation<dim>::active_cell_iterator
  cell = triangulation.begin_active(),
  endc = triangulation.end();
for (; cell!=endc; ++cell)
  cell->set_user_flag();

Using C++11's range-based for loops, this is now entirely equivalent to the following:

Triangulation<dim> triangulation;
...
for (auto cell : triangulation.active_cell_iterators())
  cell->set_user_flag();

Returns: The half open range [this->begin_active(), this->end())

Definition at line 10632 of file tria.cc.

◆ cell_iterators_on_level() [2/3]

template<int dim, int spacedim>

IteratorRange< typename Triangulation< dim, spacedim >::cell_iterator > Triangulation< dim, spacedim >::cell_iterators_on_level ( const unsigned int level ) const

Return an iterator range that contains all cells (active or not) that make up the given level of this triangulation. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Parameters

[in] level A given level in the refinement hierarchy of this triangulation.

Returns: The half open range [this->begin(level), this->end(level))

Precondition: level must be less than this->n_levels().

Definition at line 10643 of file tria.cc.

◆ active_cell_iterators_on_level() [2/3]

template<int dim, int spacedim>

IteratorRange< typename Triangulation< dim, spacedim >::active_cell_iterator > Triangulation< dim, spacedim >::active_cell_iterators_on_level ( const unsigned int level ) const

Return an iterator range that contains all active cells that make up the given level of this triangulation. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Parameters

[in] level A given level in the refinement hierarchy of this triangulation.

Returns: The half open range [this->begin_active(level), this->end(level))

Precondition: level must be less than this->n_levels().

Definition at line 10654 of file tria.cc.

◆ cell_iterators() [3/3]

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::cell_iterator > DoFHandler< dim, spacedim >::cell_iterators ( ) const

Return an iterator range that contains all cells (active or not) that make up this DoFHandler. Such a range is useful to initialize range- based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Returns: The half open range [this->begin(), this->end())

Definition at line 1054 of file dof_handler.cc.

◆ active_cell_iterators() [3/3]

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::active_cell_iterator > DoFHandler< dim, spacedim >::active_cell_iterators ( ) const

Return an iterator range that contains all active cells that make up this DoFHandler. Such a range is useful to initialize range-based for loops as supported by C++11, see also C++11 standard.

Range-based for loops are useful in that they require much less code than traditional loops (see here for a discussion of how they work). An example is that without range-based for loops, one often writes code such as the following:

DoFHandler<dim> dof_handler;
...
typename DoFHandler<dim>::active_cell_iterator
  cell = dof_handler.begin_active(),
  endc = dof_handler.end();
for (; cell!=endc; ++cell)
  {
    fe_values.reinit (cell);
    ...do the local integration on 'cell'...;
  }

Using C++11's range-based for loops, this is now entirely equivalent to the following:

DoFHandler<dim> dof_handler;
...
for (auto cell : dof_handler.active_cell_iterators())
  {
    fe_values.reinit (cell);
    ...do the local integration on 'cell'...;
  }

Returns: The half open range [this->begin_active(), this->end())

Definition at line 1064 of file dof_handler.cc.

◆ cell_iterators_on_level() [3/3]

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::cell_iterator > DoFHandler< dim, spacedim >::cell_iterators_on_level ( const unsigned int level ) const

Return an iterator range that contains all cells (active or not) that make up the given level of this DoFHandler. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Parameters

[in] level A given level in the refinement hierarchy of this triangulation.

Returns: The half open range [this->begin(level), this->end(level))

Precondition: level must be less than this->n_levels().

Definition at line 1075 of file dof_handler.cc.

◆ active_cell_iterators_on_level() [3/3]

template<int dim, int spacedim>

IteratorRange< typename DoFHandler< dim, spacedim >::active_cell_iterator > DoFHandler< dim, spacedim >::active_cell_iterators_on_level ( const unsigned int level ) const

Return an iterator range that contains all active cells that make up the given level of this DoFHandler. Such a range is useful to initialize range-based for loops as supported by C++11. See the example in the documentation of active_cell_iterators().

Parameters

[in] level A given level in the refinement hierarchy of this triangulation.

Returns: The half open range [this->begin_active(level), this->end(level))

Precondition: level must be less than this->n_levels().

Definition at line 1086 of file dof_handler.cc.

◆ filter_iterators() [3/4]

template<typename BaseIterator , typename Predicate >

IteratorRange< FilteredIterator< BaseIterator > > filter_iterators	(	IteratorRange< BaseIterator >	i,
		const Predicate &	p
	)

DoFHandler<dim> dof_handler;
...
for (auto cell : dof_handler.active_cell_iterators())
  {
    if (cell->is_locally_owned())
      {
        fe_values.reinit (cell);
        ...do the local integration on 'cell'...;
      }
  }

by:

DoFHandler<dim> dof_handler;
...
for (auto cell : filter_iterators(dof_handler.active_cell_iterators(),
                                 IteratorFilters::LocallyOwnedCell())
  {
    fe_values.reinit (cell);
    ...do the local integration on 'cell'...;
  }

Author: Bruno Turcksin, 2016

Definition at line 838 of file filtered_iterator.h.

◆ filter_iterators() [4/4]

template<typename BaseIterator , typename Predicate , typename... Targs>

IteratorRange< typename internal::FilteredIteratorImplementation::NestFilteredIterators< BaseIterator, std::tuple< Predicate, Targs... > >::type > filter_iterators	(	IteratorRange< BaseIterator >	i,
		const Predicate &	p,
		const Targs...	args
	)

DoFHandler<dim> dof_handler;
...
for (auto cell : dof_handler.active_cell_iterators())
  {
    if (cell->is_locally_owned())
      {
        if (cell->at_boundary())
          {
            fe_values.reinit (cell);
            ...do the local integration on 'cell'...;
          }
      }
  }

by:

DoFHandler<dim> dof_handler;
...
for (auto cell : filter_iterators(dof_handler.active_cell_iterators(),
                                 IteratorFilters::LocallyOwnedCell(),
                                 IteratorFilters::AtBoundary())
  {
    fe_values.reinit (cell);
    ...do the local integration on 'cell'...;
  }

Author: Bruno Turcksin, 2016

Definition at line 887 of file filtered_iterator.h.

Classes

Functions

Cell iterator functions returning ranges of iterators

Cell iterator functions returning ranges of iterators

Cell iterator functions returning ranges of iterators

Detailed Description

Function Documentation

◆ new_thread()

◆ new_task()

◆ cell_iterators() [1/3]

◆ active_cell_iterators() [1/3]

◆ mg_cell_iterators()

◆ cell_iterators_on_level() [1/3]

◆ active_cell_iterators_on_level() [1/3]

◆ mg_cell_iterators_on_level()

◆ filter_iterators() [1/4]

◆ filter_iterators() [2/4]

◆ cell_iterators() [2/3]

◆ active_cell_iterators() [2/3]

◆ cell_iterators_on_level() [2/3]

◆ active_cell_iterators_on_level() [2/3]

◆ cell_iterators() [3/3]

◆ active_cell_iterators() [3/3]

◆ cell_iterators_on_level() [3/3]

◆ active_cell_iterators_on_level() [3/3]

◆ filter_iterators() [3/4]

◆ filter_iterators() [4/4]