Inheritance diagram for xtd::collections::object_model::read_only_collection< type_t >:

Definition

template<class type_t>
class xtd::collections::object_model::read_only_collection< type_t >

Provides the base class for a generic read-only collection.

template<class type_t>

class read_only_collection : public xtd::object, public xtd::collections::generic::ilist<type_t>

xtd::collections::generic::ilist

Represents a collection of objects that can be individually accessed by index.

Definition ilist.hpp:41

xtd::collections::object_model::read_only_collection

Provides the base class for a generic read-only collection.

Definition read_only_collection.hpp:38

xtd::object

Supports all classes in the xtd class hierarchy and provides low-level services to derived classes....

Definition object.hpp:43

Header: #include <xtd/collections/object_model/read_only_collection>

Namespace: xtd::collections::object_model

Library: xtd.core

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Public Aliases
using	value_type = type_t
	Represents the list value type.

using	base_type = ptr< xtd::collections::generic::ilist< value_type > >
	Represents the list base type.

using	size_type = xtd::size
	Represents the list size type (usually xtd::size).

using	difference_type = xtd::ptrdiff
	Represents the list difference type (usually xtd::ptrdiff).

using	reference = value_type &
	Represents the reference of list value type.

using	const_reference = const value_type &
	Represents the const reference of list value type.

using	pointer = value_type *
	Represents the pointer of list value type.

using	const_pointer = const value_type *
	Represents the const pointer of list value type.

using	iterator = typename generic::icollection< type_t >::iterator
	Represents the iterator of list value type.

using	const_iterator = typename generic::icollection< type_t >::const_iterator
	Represents the const iterator of list value type.

Public Fields
static constexpr xtd::size	npos
	This is a special value equal to the maximum value representable by the type xtd::size.

Public Constructors
	read_only_collection (ptr< generic::ilist< value_type > > list)
	Initializes a new instance of the xtd::collections::object_model::read_only_collection <type_t> class that is a read-only wrapper around the specified list.

Public Properties
xtd::size	count () const noexcept override
	Gets the number of elements contained in the xtd::collections::object_model::read_only_collection <type_t> instance.

const xtd::object &	sync_root () const noexcept override
	Gets an object that can be used to synchronize access to the the xtd::collections::generic::icollection <type_t>.

static const read_only_collection< value_type > &	empty ()
	Gets an empty xtd::collections::object_model::read_only_collection <type_t>.

Public Methods
bool	contains (const type_t &item) const noexcept override
	Determines whether an element is in the xtd::collections::object_model::read_only_collection <type_t>.

void	copy_to (xtd::array< type_t > &array, xtd::size array_index) const override
	Copies the entire xtd::collections::object_model::read_only_collection <type_t> to a compatible one-dimensional Array, starting at the specified index of the target array.

generic::enumerator< type_t >	get_enumerator () const noexcept override
	Returns an enumerator that iterates through the xtd::collections::object_model::read_only_collection <type_t>.

xtd::size	index_of (const type_t &item) const noexcept override
	Searches for the specified object and returns the zero-based index of the first occurrence within the entire xtd::collections::object_model::read_only_collection <type_t>.

Public Operators
const_reference	operator[] (size_type index) const override
	Returns a reference to the element at specified location pos.

Protected Properties
base_type	items () noexcept
	Returns the xtd::collections::generic::ilist <type_t> that the xtd::collections::object_model::read_only_collection <type_t> wraps.

Additional Inherited Members
Public Types inherited from xtd::collections::generic::ilist< type_t >
using	iterator = typename icollection< type_t >::iterator
	Represents the iterator of xtd::collections::generic::ienumerable value type.

using	const_iterator = typename icollection< type_t >::const_iterator
	Represents the const iterator of xtd::collections::generic::ienumerable value type.

Public Types inherited from xtd::collections::generic::icollection< type_t >
using	value_type = typename xtd::collections::generic::ienumerable< type_t >::value_type
	Represents the xtd::collections::generic::icollection value type.

using	iterator = typename xtd::collections::generic::ienumerable< type_t >::iterator
	Represents the iterator of xtd::collections::generic::ienumerable value type.

using	const_iterator = typename xtd::collections::generic::ienumerable< type_t >::const_iterator
	Represents the const iterator of xtd::collections::generic::ienumerable value type.

Public Types inherited from xtd::collections::generic::ienumerable< type_t >
using	value_type = type_t
	Represents the xtd::collections::generic::ienumerable value type.

using	iterator = typename xtd::collections::generic::extensions::enumerable_iterators< type_t, xtd::collections::generic::ienumerable< type_t > >::iterator
	Represents the iterator of xtd::collections::generic::ienumerable value type.

using	const_iterator = typename xtd::collections::generic::extensions::enumerable_iterators< type_t, xtd::collections::generic::ienumerable< type_t > >::const_iterator
	Represents the const iterator of xtd::collections::generic::ienumerable value type.

Public Types inherited from xtd::collections::generic::extensions::enumerable_iterators< type_t, xtd::collections::generic::ienumerable< type_t > >
using	iterator = enumerable_iterator
	Represents the iterator of enumarable value type.

using	const_iterator = const enumerable_iterator
	Represents the const iterator of enumarable value type.

Public Types inherited from xtd::collections::generic::extensions::enumerable< ienumerable< type_t >, type_t >
using	enumerable_type = ienumerable< type_t >
	Represents the ienumerable enumerable type.

using	source_type = type_t
	Represents the ienumerable source type.

using	ienumerable = typename xtd::linq::enumerable::ienumerable< type_t >
	Represents the ienumerable value type.

using	list = typename xtd::linq::enumerable::list< type_t >
	Represents the list value type.

Static Public Attributes inherited from xtd::collections::generic::ilist< type_t >
static constexpr xtd::size	npos
	This is a special value equal to the maximum value representable by the type xtd::size.

Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.

virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object.

virtual xtd::size	get_hash_code () const noexcept
	Serves as a hash function for a particular type.

virtual type_object	get_type () const noexcept
	Gets the type of the current instance.

template<class object_t >
xtd::uptr< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.

virtual xtd::string	to_string () const noexcept
	Returns a xtd::string that represents the current object.

Public Member Functions inherited from xtd::collections::generic::ilist< type_t >
Public Member Functions inherited from xtd::collections::generic::icollection< type_t >
Public Member Functions inherited from xtd::collections::generic::ienumerable< type_t >
Public Member Functions inherited from xtd::collections::generic::extensions::enumerable_iterators< type_t, xtd::collections::generic::ienumerable< type_t > >
virtual const_iterator	begin () const
	Returns an iterator to the first element of the enumarable.

virtual iterator	begin ()
	Returns an iterator to the first element of the enumarable.

virtual const_iterator	cbegin () const
	Returns an iterator to the first element of the enumarable.

virtual const_iterator	cend () const
	Returns an iterator to the element following the last element of the enumarable.

virtual const_iterator	end () const
	Returns an iterator to the element following the last element of the enumarable.

virtual iterator	end ()
	Returns an iterator to the element following the last element of the enumarable.

Public Member Functions inherited from xtd::collections::generic::extensions::enumerable< ienumerable< type_t >, type_t >
type_t	aggregate (const std::function< type_t(const type_t &, const type_t &)> &func) const
	Applies an accumulator function over a sequence.

type_t	aggregate (const type_t &seed, const std::function< type_t(const type_t &, const type_t &)> &func) const
	Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value.

accumulate_t	aggregate (const accumulate_t &seed, const std::function< accumulate_t(const type_t &, const accumulate_t &)> &func) const
	Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value.

type_t	aggregate (const type_t &seed, const std::function< type_t(const type_t &, const type_t &)> &func, const std::function< type_t(const type_t &)> &result_selector) const
	Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value, and the specified function is used to select the result value.

result_t	aggregate (const accumulate_t &seed, const std::function< accumulate_t(const type_t &, const accumulate_t &)> &func, const std::function< result_t(const accumulate_t &)> &result_selector) const
	Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value, and the specified function is used to select the result value.

bool	all (const std::function< bool(const type_t &)> &predicate) const
	Determines whether all elements of a sequence satisfy a condition.

bool	any () const noexcept
	Determines whether a sequence contains any elements.

bool	any (const std::function< bool(const type_t &)> &predicate) const
	Determines whether any element of a sequence satisfies a condition.

const ienumerable< type_t > &	append (const type_t &element) const noexcept
	Appends a value to the end of the sequence.

const ienumerable< type_t > &	as_enumerable () const noexcept
	Returns the input typed as xtd::collections::generic::ienumerable <type_t>.

auto	average () const noexcept
	Computes the average of a sequence of source_t values.

const ienumerable< result_t > &	cast () const noexcept
	Casts the elements of an xtd::collections::generic::ienumerable to the specified type.

const ienumerable< xtd::array< type_t > > &	chunk (size_t size) const
	Splits the elements of a sequence into chunks of size at most size.

const ienumerable< type_t > &	concat (const ienumerable< type_t > &second) const noexcept
	Concatenates two sequences.

bool	contains (const type_t &value) const noexcept
	Determines whether a sequence contains a specified element by using the default equality comparer.

bool	contains (const type_t &value, const xtd::collections::generic::iequality_comparer< type_t > &comparer) const noexcept
	Determines whether a sequence contains a specified element by using a specified equality comparer.

size_t	count () const noexcept
	Returns the number of elements in current sequence.

size_t	count (const std::function< bool(const type_t &)> &predicate) const noexcept
	Returns a number that represents how many elements in the specified sequence satisfy a condition.

xtd::size	count (const type_t &value) const noexcept
	Returns the number of elements with the specified value.

const ienumerable< key_value_pair< key_t, xtd::size > > &	count_by (const std::function< key_t(const type_t &)> &key_selector) const noexcept
	Returns the count of elements in the current sequence grouped by key.

const ienumerable< key_value_pair< key_t, xtd::size > > &	count_by (const std::function< key_t(const type_t &)> &key_selector, const iequality_comparer< key_t > &key_comparer) const noexcept
	Returns the count of elements in the current sequence grouped by key.

const ienumerable< type_t > &	default_if_empty () const noexcept
	Returns the elements of the specified sequence or the type parameter's default value in a singleton collection if the current sequence is empty.

const ienumerable< type_t > &	default_if_empty (const type_t &default_value) const noexcept
	Returns the elements of the specified sequence or the specified value in a singleton collection if the current sequence is empty.

type_t	first_or_default (const std::function< bool(const type_t &)> &predicate, const type_t &default_value) const noexcept
	Returns the first element of the sequence that satisfies a condition, or a specified default value if no such element is found.

type_t	first_or_default (const std::function< bool(const type_t &)> &predicate) const noexcept
	Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.

type_t	first_or_default (const type_t default_value) const noexcept
	Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.

type_t	first_or_default () const noexcept
	Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.

const ienumerable< result_t > &	select (const std::function< result_t(const type_t &)> &selector) const
	Projects each element of a sequence into a new form.

const ienumerable< type_t > &	select (const std::function< type_t(const type_t &)> &selector) const
	Projects each element of a sequence into a new form.

const ienumerable< result_t > &	select (const std::function< result_t(const type_t &, size_t index)> &selector) const
	Projects each element of a sequence into a new form by incorporating the element's index.

const ienumerable< type_t > &	select (const std::function< type_t(const type_t &, size_t index)> &selector) const
	Projects each element of a sequence into a new form by incorporating the element's index.

const list< type_t > &	to_list () const noexcept
	Creates a xtd::collections::generic::list <type_t> from an xtd::collections::generic::ienumerable <type_t>.

const ienumerable< type_t > &	where (const std::function< bool(const type_t &)> &predicate) const
	Filters a sequence of values based on a predicate.

const ienumerable< type_t > &	where (const std::function< bool(const type_t &, size_t)> &predicate) const
	Filters a sequence of values based on a predicate. Each element's index is used in the logic of the predicate function.

Public Member Functions inherited from xtd::collections::generic::extensions::collection_operators< type_t, icollection< type_t > >
virtual icollection< type_t > &	operator<< (const type_t &item)
	The shift left operator adds an item to the xtd::collections::generic::icollection <type_t>.

virtual icollection< type_t > &	operator>> (const type_t &item)
	The shift right operator removes tthe first occurrence of a specific object from the xtd::collections::generic::icollection <type_t>.

Static Public Member Functions inherited from xtd::object
template<class object_a_t , class object_b_t >
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.

template<class object_a_t , class object_b_t >
static bool	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are the same instance.

Static Public Member Functions inherited from xtd::collections::generic::extensions::enumerable_iterators< type_t, xtd::collections::generic::ienumerable< type_t > >
static target_collection_t::const_iterator	to_iterator (typename source_collection_t::const_iterator &value, const source_collection_t &source_collection, const target_collection_t &target_collection) noexcept
	Converts source iterator to target iterator.

static target_collection_t::iterator	to_iterator (typename source_collection_t::iterator &value, const source_collection_t &source_collection, const target_collection_t &target_collection) noexcept
	Converts source iterator to target iterator.

static target_collection_t::const_iterator	to_iterator (typename source_collection_t::const_iterator &value, source_collection_t &source_collection, target_collection_t &target_collection) noexcept
	Converts source iterator to target iterator.

static target_collection_t::iterator	to_iterator (typename source_collection_t::iterator &value, source_collection_t &source_collection, target_collection_t &target_collection) noexcept
	Converts source iterator to target iterator.

Member Typedef Documentation

◆ value_type

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::value_type = type_t

Represents the list value type.

◆ base_type

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::base_type = ptr<xtd::collections::generic::ilist<value_type> >

Represents the list base type.

◆ size_type

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::size_type = xtd::size

Represents the list size type (usually xtd::size).

◆ difference_type

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::difference_type = xtd::ptrdiff

Represents the list difference type (usually xtd::ptrdiff).

◆ reference

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::reference = value_type&

Represents the reference of list value type.

◆ const_reference

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::const_reference = const value_type&

Represents the const reference of list value type.

◆ pointer

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::pointer = value_type*

Represents the pointer of list value type.

◆ const_pointer

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::const_pointer = const value_type*

Represents the const pointer of list value type.

◆ iterator

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::iterator = typename generic::icollection<type_t>::iterator

Represents the iterator of list value type.

◆ const_iterator

template<class type_t >

using xtd::collections::object_model::read_only_collection< type_t >::const_iterator = typename generic::icollection<type_t>::const_iterator

Represents the const iterator of list value type.

Constructor & Destructor Documentation

◆ read_only_collection()

template<class type_t >

xtd::collections::object_model::read_only_collection< type_t >::read_only_collection ( ptr< generic::ilist< value_type > > list )

inlineexplicit

Initializes a new instance of the xtd::collections::object_model::read_only_collection <type_t> class that is a read-only wrapper around the specified list.

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Remarks: To prevent any modifications to list, expose list only through this wrapper.; A collection that is read-only is simply a collection with a wrapper that prevents modifying the collection; therefore, if changes are made to the underlying collection, the read-only collection reflects those changes.; This constructor is an O(1) operation.

Member Function Documentation

◆ count()

template<class type_t >

xtd::size xtd::collections::object_model::read_only_collection< type_t >::count ( ) const

inlineoverridevirtualnoexcept

Gets the number of elements contained in the xtd::collections::object_model::read_only_collection <type_t> instance.

Returns: The number of elements contained in the xtd::collections::object_model::read_only_collection <type_t> instance.

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Remarks: Retrieving the value of this property is an O(1) operation.

Implements xtd::collections::generic::icollection< type_t >.

◆ empty()

template<class type_t >

static const read_only_collection< value_type > & xtd::collections::object_model::read_only_collection< type_t >::empty ( )

inlinestatic

Gets an empty xtd::collections::object_model::read_only_collection <type_t>.

Returns: An empty xtd::collections::object_model::read_only_collection <type_t>.

Remarks: The returned instance is immutable and will always be empty.

◆ sync_root()

template<class type_t >

const xtd::object & xtd::collections::object_model::read_only_collection< type_t >::sync_root ( ) const

inlineoverridevirtualnoexcept

Gets an object that can be used to synchronize access to the the xtd::collections::generic::icollection <type_t>.

Returns: An object that can be used to synchronize access to the the xtd::collections::generic::icollection <type_t>.

Remarks: For collections whose underlying store is not publicly available, the expected implementation is to return the current instance. Note that the pointer to the current instance might not be sufficient for collections that wrap other collections; those should return the underlying collection's sync_root property.; Most collection classes in the xts::.collections namespace also implement a synchronized method, which provides a synchronized wrapper around the underlying collection. However, derived classes can provide their own synchronized version of the collection using the xtd::collections::generic::icollection::sync_root property. The synchronizing code must perform operations on the xtd::collections::generic::icollection::sync_root property of the collection, not directly on the collection. This ensures proper operation of collections that are derived from other objects. Specifically, it maintains proper synchronization with other threads that might be simultaneously modifying the collection instance.; In the absence of a synchronized method on a collection, the expected usage for the xtd::collections::generic::icollection::sync_root looks as follows:
icollection& my_collection = some_collection;

lock_(my_collection.sync_root()) {

// Some operation on the collection, which is now thread safe.

}

@encode

@remarks Enumerating through a collection is intrinsically not a thread-safe procedure. Even when a collection is synchronized, other threads can still modify the collection, which causes the enumerator to throw an exception. To guarantee thread safety during enumeration, you can either lock the collection during the entire enumeration or catch the exceptions resulting from changes made by other threads.

@remarks The following code example shows how to lock the collection using the xtd::collections::generic::icollection::sync_root property during the entire enumeration.

@code

icollection& my_collection = some_collection;

lock_(my_collection.sync_root()) {

for (auto item : my_collection) {

// Insert your code here.

}

}

xtd::collections::generic::icollection
Defines methods to manipulate generic collections.
Definition icollection.hpp:45

xtd::collections::generic::icollection::sync_root
virtual const xtd::object & sync_root() const noexcept=0
Gets an object that can be used to synchronize access to the the xtd::collections::generic::icollecti...

xtd::exception
Defines the base class for predefined exceptions in the xtd namespace.
Definition exception.hpp:28

xtd::threading::lock_guard
Provides a mechanism that synchronizes access to objects with xtd::threading::monitor.
Definition lock_guard.hpp:32

lock_
#define lock_(object)
The lock_ keyword marks a statement block as a critical section by obtaining the mutual-exclusion loc...
Definition lock.hpp:85

xtd::is
bool is(std::any value)
Checks if the result of an expression is compatible with a given type.
Definition is.hpp:365

xtd::platform_id::other
@ other
The operating system is other.

xtd::console_key::a
@ a
The A key.

xtd::collections::generic::enumerator
Supports a simple iteration over a generic collection.
Definition enumerator.hpp:38

Implements xtd::collections::generic::icollection< type_t >.

◆ contains()

template<class type_t >

bool xtd::collections::object_model::read_only_collection< type_t >::contains ( const type_t & item ) const

inlineoverridevirtualnoexcept

Determines whether an element is in the xtd::collections::object_model::read_only_collection <type_t>.

Parameters

item	The object to locate in the xtd::collections::object_model::read_only_collection <type_t>. The value can be null for reference types.

Returns: true if value is found in the xtd::collections::object_model::read_only_collection <type_t>; otherwise, false.

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Remarks: This method determines equality using the default equality comparer xtd::collections::generic::equality_comparer::default_comparer.; This method performs a linear search; therefore, this method is an O(n) operation, where n is xtd::collections::object_model::read_only_collection::count.

Implements xtd::collections::generic::icollection< type_t >.

◆ copy_to()

template<class type_t >

void xtd::collections::object_model::read_only_collection< type_t >::copy_to	(	xtd::array< type_t > &	array,
		xtd::size	array_index
	)		const

inlineoverridevirtual

Copies the entire xtd::collections::object_model::read_only_collection <type_t> to a compatible one-dimensional Array, starting at the specified index of the target array.

Parameters

array	The one-dimensional xtd::array that is the destination of the elements copied from xtd::collections::object_model::read_only_collection <type_t>. The xtd::array must have zero-based indexing.
array_index	The zero-based index in array at which copying begins.

Exceptions

xtd::argument_exception The number of elements in the source xtd::collections::object_model::read_only_collection <type_t> is greater than the available space from index to the end of the destination array.

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Remarks: This method uses xtd::array::copy to copy the elements.; The elements are copied to the xtd::array in the same order that the enumerator iterates through the xtd::collections::object_model::read_only_collection <type_t>.; This method is an O(n) operation, where n is xtd::collections::object_model::read_only_collection::count.

Implements xtd::collections::generic::icollection< type_t >.

◆ get_enumerator()

template<class type_t >

generic::enumerator< type_t > xtd::collections::object_model::read_only_collection< type_t >::get_enumerator ( ) const

inlineoverridevirtualnoexcept

Returns an enumerator that iterates through the xtd::collections::object_model::read_only_collection <type_t>.

Returns: An xtd::collections::generic::enumerator<T> for the xtd::collections::object_model::read_only_collection <type_t>.

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Remarks: The for each statement of the C++ language hides the complexity of the enumerators. Therefore, using for each is recommended, instead of directly manipulating the enumerator.; Enumerators can be used to read the data in the collection, but they cannot be used to modify the underlying collection.; Initially, the enumerator is positioned before the first element in the collection. At this position, xtd::collections::generic::enumerator::current is undefined. Therefore, you must call xtd::collections::generic::enumerator::move_next to advance the enumerator to the first element of the collection before reading the value of xtd::collections::generic::enumerator::current.; xtd::collections::generic::enumerator::current returns the same object until xtd::collections::generic::enumerator::move_next is called. xtd::collections::generic::enumerator::move_next sets xtd::collections::generic::enumerator::current to the next element.; If xtd::collections::generic::enumerator::move_next passes the end of the collection, the enumerator is positioned after the last element in the collection and xtd::collections::generic::enumerator::move_next returns false. When the enumerator is at this position, subsequent calls to MoveNext also return false. If the last call to MoveNext returned false, Current is undefined. You cannot set xtd::collections::generic::enumerator::current to the first element of the collection again; you must create a new enumerator instance instead.; An enumerator remains valid as long as the collection remains unchanged. If changes are made to the collection, such as adding, modifying, or deleting elements, the enumerator is irrecoverably invalidated and its behavior is undefined.; The enumerator does not have exclusive access to the collection; therefore, enumerating through a collection is intrinsically not a thread-safe procedure. To guarantee thread safety during enumeration, you can lock the collection during the entire enumeration. To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization.; Default implementations of collections in xtd::collections::generic are not synchronized.; This method is an O(1) operation

Implements xtd::collections::generic::ienumerable< type_t >.

◆ index_of()

template<class type_t >

xtd::size xtd::collections::object_model::read_only_collection< type_t >::index_of ( const type_t & item ) const

inlineoverridevirtualnoexcept

Searches for the specified object and returns the zero-based index of the first occurrence within the entire xtd::collections::object_model::read_only_collection <type_t>.

Parameters

item	The object to locate in the xtd::collections::object_model::read_only_collection <type_t>.

Returns: The zero-based index of the first occurrence of item within the entire xtd::collections::object_model::read_only_collection <type_t>, if found; otherwise, xtd::collections::object_model::read_only_collection::npos.

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Remarks: The xtd::collections::object_model::read_only_collection <type_t> is searched forward starting at the first element and ending at the last element.; This method determines equality using the default comparer xtd::collections::generic::equality_comparer::default_comparer.; This method performs a linear search; therefore, this method is an O(n) operation, where n is xtd::collections::object_model::read_only_collection::count.

Implements xtd::collections::generic::ilist< type_t >.

◆ operator[]()

template<class type_t >

const_reference xtd::collections::object_model::read_only_collection< type_t >::operator[] ( size_type index ) const

inlineoverridevirtual

Returns a reference to the element at specified location pos.

Parameters

index The position of the element to return.

Returns: Reference to the requested element.

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Remarks: Retrieving the value of this property is an O(1) operation.; This property provides the ability to access a specific element in the collection by using the following C++ syntax: my_collection[index].; Retrieving the value of this property is an O(1) operation.

Implements xtd::collections::generic::ilist< type_t >.

◆ items()

template<class type_t >

base_type xtd::collections::object_model::read_only_collection< type_t >::items ( )

inlineprotectednoexcept

Returns the xtd::collections::generic::ilist <type_t> that the xtd::collections::object_model::read_only_collection <type_t> wraps.

Returns: The xtd::collections::generic::ilist <type_t> that the xtd::collections::object_model::read_only_collection <type_t> wraps.

Examples: The following code example demonstrates several members of the xtd::collections::object_model::read_only_collection <type_t> class. The code example creates a xtd::collections::generic::list <type_t> of strings and adds four dinosaur names to it. The code example then wraps the list in a xtd::collections::object_model::read_only_collection <type_t>.

After demonstrating the xtd::collections::object_model::read_only_collection::count, xtd::collections::object_model::read_only_collection::contains, xtd::collections::object_model::read_only_collection:: opertor [], and xtd::collections::generic::ilist::index_of members, the code example shows that the xtd::collections::object_model::read_only_collection <type_t> is just a wrapper for the original xtd::collections::generic::list <type_t> by adding a new item to the xtd::collections::generic::list <type_t> and displaying the contents of the xtd::collections::object_model::read_only_collection <type_t>.

Finally, the code example creates an array larger than the collection and uses the xtd::collections::object_model::read_only_collection::copy_to method to insert the elements of the collection into the middle of the array.

#include <xtd/xtd>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class example {
public:
  static auto main() -> void {
    auto dinosaurs = list<string> {};
    
    dinosaurs.add("Tyrannosaurus");
    dinosaurs.add("Amargasaurus");
    dinosaurs.add("Deinonychus");
    dinosaurs.add("Compsognathus");
 
    auto read_only_dinosaurs = dinosaurs.as_read_only();
 
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
    
    console::write_line("\ncount: {0}", read_only_dinosaurs.count());
    
    console::write_line("\ncontains(\"Deinonychus\"): {0}", dinosaurs.contains("Deinonychus"));
    
    console::write_line("\nread_only_dinosaurs[3]: {0}", dinosaurs[3]);
    
    console::write_line("\nindex_of(\"Compsognathus\"): {0}", read_only_dinosaurs.index_of("Compsognathus"));
    
    console::write_line("\nInsert into the wrapped List:");
    console::write_line("insert(2, \"Oviraptor\")");
    dinosaurs.insert(2, "Oviraptor");
    
    console::write_line();
    for (auto dinosaur : read_only_dinosaurs)
      console::write_line(dinosaur);
 
    auto dino_array = array<string>(read_only_dinosaurs.count() + 2);
    read_only_dinosaurs.copy_to(dino_array, 1);
    
    console::write_line("\nCopied array has {0} elements:", dino_array.size());
    for (auto dinosaur : dino_array )
      console::write_line("\"{0}\"", dinosaur);
  }
};
 
startup_(example::main);
 
// This code produces the following output :
//
// Tyrannosaurus
// Amargasaurus
// Deinonychus
// Compsognathus
//
// count: 4
//
// contains("Deinonychus"): true
//
// read_only_dinosaurs[3]: Compsognathus
//
// index_of("Compsognathus"): 3
//
// Insert into the wrapped List:
// insert(2, "Oviraptor")
//
// Tyrannosaurus
// Amargasaurus
// Oviraptor
// Deinonychus
// Compsognathus
//
// Copied array has 7 elements:
// ""
// "Tyrannosaurus"
// "Amargasaurus"
// "Oviraptor"
// "Deinonychus"
// "Compsognathus"
// ""

Remarks: Retrieving the value of this property is an O(1) operation.

Member Data Documentation

◆ npos

template<class type_t >

constexpr xtd::size xtd::collections::object_model::read_only_collection< type_t >::npos

inlinestaticconstexpr

This is a special value equal to the maximum value representable by the type xtd::size.

The documentation for this class was generated from the following file:

xtd.core/include/xtd/collections/object_model/read_only_collection.hpp

Definition

Public Aliases

Public Fields

Public Constructors

Public Properties

Public Methods

Public Operators

Protected Properties

Additional Inherited Members

Member Typedef Documentation

◆ value_type

◆ base_type

◆ size_type

◆ difference_type

◆ reference

◆ const_reference

◆ pointer

◆ const_pointer

◆ iterator

◆ const_iterator

Constructor & Destructor Documentation

◆ read_only_collection()

Member Function Documentation

◆ count()

◆ empty()

◆ sync_root()

◆ contains()

◆ copy_to()

◆ get_enumerator()

◆ index_of()

◆ operator[]()

◆ items()

Member Data Documentation

◆ npos