xtd::collections::generic::idictionary< key_t, value_t > Class Template Reference

Inheritance diagram for xtd::collections::generic::idictionary< key_t, value_t >:

Definition

template<typename key_t, typename value_t>
class xtd::collections::generic::idictionary< key_t, value_t >

Represents a generic collection of key/value pairs.

Definition

template<typename key_t, typename value_t>
class idictionary : public xtd::collections::generic::icollection<xtd::collections::generic::key_value_pair<key_t, value_t>>;

Header

#include <xtd/collections/generic/idictionary>

Namespace

xtd::collections::generic

Library

xtd.core

Remarks

The xtd::collections::generic::idictionary <key_t, value_t> interface is the base interface for generic collections of key/value pairs.

Each element is a key/value pair stored in a xtd::collections::generic::key_value_pair <key_t, value_t> object.

Each pair must have a unique key. Implementations can vary in whether they allow key to be empty. The value can be empty and does not have to be unique. The idictionary <key_t, value_t> interface allows the contained keys and values to be enumerated, but it does not imply any particular sort order.

The for each statement returns an object of the type of the elements in the collection. Since each element of the xtd::collections::generic::idictionary <key_t, value_t> is a key/value pair, the element type is not the type of the key or the type of the value. Instead, the element type is xtd::collections::generic::key_value_pair <key_t, value_t>. For example:

for (const key_value_pair<int, string>& kvp : my_dictionary)
  console::write_line("key = {}, value = {}", kvp.key(), kvp.value());

Or with auto key type and the value type. For example:

for (const auto& [key, value] : my_dictionary)
  console::write_line("key = {}, value = {}", key, value);

Public Aliases
using	key_type
	Represents the dictionary key type.
using	mapped_type
	Represents the dictionary mapped type.
using	value_type
	Represents the xtd::collections::generic::idictionary value type.
using	iterator
	Represents the iterator of xtd::collections::generic::ienumerable value type.
using	const_iterator
	Represents the const iterator of xtd::collections::generic::ienumerable value type.
using	key_collection
	Represents the idictionary key collection type.
using	value_collection
	Represents the idictionary value collection type.

Public Properties
virtual auto	count () const noexcept -> xtd::usize=0
	Gets the number of elements contained in the xtd::collections::generic::icollection <type_t>.
virtual auto	is_read_only () const noexcept -> bool=0
	Gets a value indicating whether the xtd::collections::generic::icollection <type_t> is read-only.
virtual auto	is_synchronized () const noexcept -> bool=0
	Gets a value indicating whether access to the xtd::collections::generic::icollection <type_t> is synchronized (thread safe).
virtual auto	keys () const noexcept -> key_collection=0
	Gets an xtd::collections::generic::icollection <type_t> containing the keys of the xtd::collections::generic::idictionary <key_t, value_t>.
virtual auto	sync_root () const noexcept -> const xtd::object &=0
	Gets an object that can be used to synchronize access to the the xtd::collections::generic::icollection <type_t>.
virtual auto	values () const noexcept -> value_collection=0
	Gets an xtd::collections::generic::icollection <type_t> containing the values of the xtd::collections::generic::idictionary <key_t, value_t>.

Public Methods
virtual auto	add (const xtd::collections::generic::key_value_pair< key_t, value_t > &item) -> void=0
	Adds an item to the xtd::collections::generic::icollection <type_t>.
virtual auto	add (const key_t &key, const value_t &value) -> void=0
	Adds an element with the provided key and value to the xtd::collections::generic::idictionary <key_t, value_t>.
virtual auto	clear () -> void=0
	Removes all items from the xtd::collections::generic::icollection <type_t>.
virtual auto	contains (const xtd::collections::generic::key_value_pair< key_t, value_t > &item) const noexcept -> bool=0
	Determines whether the xtd::collections::generic::icollection <type_t> contains a specific value.
virtual auto	contains_key (const key_t &key) const noexcept -> bool=0
	Determines whether the xtd::collections::generic::idictionary <key_t, value_t> contains an element with the specified key.
virtual auto	copy_to (xtd::array< xtd::collections::generic::key_value_pair< key_t, value_t > > &array, xtd::usize array_index) const -> void=0
	Copies the elements of the xtd::collections::generic::icollection <type_t> to an xtd::array, starting at a particular xtd::array index.
virtual auto	get_enumerator () const -> xtd::collections::generic::enumerator< xtd::collections::generic::key_value_pair< key_t, value_t > >=0
	Returns an enumerator that iterates through a collection.
virtual auto	remove (const xtd::collections::generic::key_value_pair< key_t, value_t > &item) -> bool=0
	Removes the first occurrence of a specific object from the xtd::collections::generic::icollection <type_t>.
virtual auto	remove (const key_t &key) noexcept -> bool=0
	Removes the element with the specified key from the xtd::collections::generic::idictionary <key_t, value_t>.
virtual auto	try_get_value (const key_t &key, value_t &value) const -> bool=0
	Gets the value associated with the specified key.

Public Operators
virtual auto	operator[] (const key_t &key) -> value_t &=0
	Gets the element with the specified key.

Additional Inherited Members
using	value_type
	Represents the xtd::collections::generic::icollection value type.
using	value_type
	Represents the xtd::collections::generic::ienumerable value type.
using	iterator
	Represents the iterator of xtd::collections::generic::ienumerable value type.
using	const_iterator
	Represents the const iterator of xtd::collections::generic::ienumerable value type.
using	iterator
	Represents the iterator of enumerable value type.
using	const_iterator
	Represents the const iterator of enumerable value type.
using	enumerable_type
	Represents the ienumerable enumerable type.
using	source_type
	Represents the ienumerable source type.
using	ienumerable
	Represents the ienumerable value type.
using	list
	Represents the list value type.
virtual auto	begin () const -> const_iterator
	Returns an iterator to the first element of the enumerable.
virtual auto	cbegin () const -> const_iterator
	Returns an iterator to the first element of the enumerable.
virtual auto	cend () const -> const_iterator
	Returns an iterator to the element following the last element of the enumerable.
virtual auto	end () const -> const_iterator
	Returns an iterator to the element following the last element of the enumerable.
auto	aggregate (const std::function< xtd::collections::generic::key_value_pair< key_t, value_t >(const xtd::collections::generic::key_value_pair< key_t, value_t > &, const xtd::collections::generic::key_value_pair< key_t, value_t > &)> &funcfunc) const -> xtd::collections::generic::key_value_pair< key_t, value_t >
	Applies an accumulator function over a sequence.
auto	all (const std::function< bool(const xtd::collections::generic::key_value_pair< key_t, value_t > &)> &predicatepredicate) const -> bool
	Determines whether all elements of a sequence satisfy a condition.
auto	any () const noexcept -> bool
	Determines whether a sequence contains any elements.
auto	append (const xtd::collections::generic::key_value_pair< key_t, value_t > &element) const noexcept
	Appends a value to the end of the sequence.
auto	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.
auto	cast () const noexcept
	Casts the elements of an xtd::collections::generic::ienumerable to the specified type.
auto	chunk (xtd::usize size) const
	Splits the elements of a sequence into chunks of size at most size.
auto	concat (const ienumerable< xtd::collections::generic::key_value_pair< key_t, value_t > > &second) const noexcept
	Concatenates two sequences.
auto	contains (const xtd::collections::generic::key_value_pair< key_t, value_t > &value) const noexcept -> bool
	Determines whether a sequence contains a specified element by using the default equality comparer.
auto	count () const noexcept -> xtd::usize
	Returns the number of elements in current sequence.
auto	count_by (const std::function< key_t(const xtd::collections::generic::key_value_pair< key_t, value_t > &)> &key_selector) const noexcept
	Returns the count of elements in the current sequence grouped by key.
auto	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.
auto	distinct () const noexcept
	Returns distinct elements from a sequence by using the default equality comparer to compare values.
auto	first_or_default (const std::function< bool(const xtd::collections::generic::key_value_pair< key_t, value_t > &)> &predicatepredicate, const xtd::collections::generic::key_value_pair< key_t, value_t > &default_value) const noexcept -> xtd::collections::generic::key_value_pair< key_t, value_t >
	Returns the first element of the sequence that satisfies a condition, or a specified default value if no such element is found.
auto	order () const
	Sorts the elements of a sequence in ascending order.
auto	order_by (const std::function< xtd::collections::generic::key_value_pair< key_t, value_t >(const xtd::collections::generic::key_value_pair< key_t, value_t > &)> &key_selector) const
	Sorts the elements of a sequence in ascending order according to a key.
auto	order_by_descending (const std::function< key_t(const xtd::collections::generic::key_value_pair< key_t, value_t > &)> &key_selector) const
	Sorts the elements of a sequence in descending order according to a key.
auto	select (auto &&selector) const
	Projects each element of a sequence into a new form.
auto	to_array () const noexcept -> xtd::array< xtd::collections::generic::key_value_pair< key_t, value_t > >
	Creates a xtd::array <type_t> from an xtd::collections::generic::ienumerable <type_t>.
auto	to_list () const noexcept -> xtd::collections::generic::list< xtd::collections::generic::key_value_pair< key_t, value_t > >
	Creates a xtd::collections::generic::list <type_t> from an xtd::collections::generic::ienumerable <type_t>.
auto	where (auto &&predicatepredicate) const
	Filters a sequence of values based on a predicate.
virtual auto	empty () const noexcept -> bool
	Checks whether the container is empty.
virtual auto	size () const noexcept -> xtd::usize
	Gets the number of elements contained in the xtd::collections::generic::icollection <type_t>.
virtual auto	operator<< (const xtd::collections::generic::key_value_pair< key_t, value_t > &item) -> icollection< xtd::collections::generic::key_value_pair< key_t, value_t > > &
	The shift left operator adds an item to the xtd::collections::generic::icollection <type_t>.
virtual auto	operator>> (const xtd::collections::generic::key_value_pair< key_t, value_t > &item) -> icollection< xtd::collections::generic::key_value_pair< key_t, value_t > > &
	The shift right operator removes the first occurrence of a specific object from the xtd::collections::generic::icollection <type_t>.
static auto	to_const_iterator (typename source_collection_t::const_iterator &value, const source_collection_t &source_collection, const target_collection_t &target_collection) noexcept -> typename target_collection_t::const_iterator
	Converts source iterator to target iterator.
static auto	to_iterator (typename source_collection_t::const_iterator &value, const source_collection_t &source_collection, const target_collection_t &target_collection) noexcept -> typename target_collection_t::const_iterator
	Converts source iterator to target iterator.

Member Typedef Documentation

key_type

template<typename key_t, typename value_t>

using xtd::collections::generic::idictionary< key_t, value_t >::key_type

Represents the dictionary key type.

mapped_type

template<typename key_t, typename value_t>

using xtd::collections::generic::idictionary< key_t, value_t >::mapped_type

Represents the dictionary mapped type.

value_type

template<typename key_t, typename value_t>

using xtd::collections::generic::idictionary< key_t, value_t >::value_type

Represents the xtd::collections::generic::idictionary value type.

iterator

template<typename key_t, typename value_t>

using xtd::collections::generic::idictionary< key_t, value_t >::iterator

Represents the iterator of xtd::collections::generic::ienumerable value type.

const_iterator

template<typename key_t, typename value_t>

using xtd::collections::generic::idictionary< key_t, value_t >::const_iterator

Represents the const iterator of xtd::collections::generic::ienumerable value type.

key_collection

template<typename key_t, typename value_t>

using xtd::collections::generic::idictionary< key_t, value_t >::key_collection

Represents the idictionary key collection type.

value_collection

template<typename key_t, typename value_t>

using xtd::collections::generic::idictionary< key_t, value_t >::value_collection

Represents the idictionary value collection type.

Member Function Documentation

count()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::count ( ) const -> xtd::usize

nodiscardpure virtualnoexcept

Gets the number of elements contained in the xtd::collections::generic::icollection <type_t>.

Returns

The number of elements contained in the xtd::collections::generic::icollection <type_t>.

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< intptr, item >, xtd::collections::generic::dictionary< key_type, mapped_type >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::dictionary< xtd::intptr, xtd::ptr< collection_type > >, xtd::collections::generic::dictionary< xtd::string, xtd::any_object >, xtd::collections::generic::dictionary< xtd::string, xtd::string >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

is_read_only()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::is_read_only ( ) const -> bool

nodiscardpure virtualnoexcept

Gets a value indicating whether the xtd::collections::generic::icollection <type_t> is read-only.

Returns

true if the xtd::collections::generic::icollection <type_t> is read-only; otherwise, false.

Remarks

A collection that is read-only does not allow the addition or removal of elements after the collection is created. Note that read-only in this context does not indicate whether individual elements of the collection can be modified, since the xtd::collections::generic::icollection <type_t> interface only supports addition and removal operations. For example, the xtd::collections::generic::icollection::is_read_only property of an array that is cast or converted to an xtd::collections::generic::icollection <type_t> object returns true, even though individual array elements can be modified.

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

is_synchronized()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::is_synchronized ( ) const -> bool

nodiscardpure virtualnoexcept

Gets a value indicating whether access to the xtd::collections::generic::icollection <type_t> is synchronized (thread safe).

Returns

true if access to the xtd::collections::generic::icollection <type_t> is synchronized (thread safe); otherwise, false.

Remarks

xtd::collections::generic::icollection::sync_root returns an object, which can be used to synchronize access to the xtd::collections::generic::icollection <type_t>.

Most collection classes in the xtd::collections namespace also implement a synchronized method, which provides a synchronized wrapper around the underlying collection.

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.

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

icollection& my_collection = some_collection;
lock_(my_collection.sync_root()) {
  for (const auto& item : my_collection) {
    // Insert your code here.
  }
}

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

keys()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::keys ( ) const -> key_collection

nodiscardpure virtualnoexcept

Gets an xtd::collections::generic::icollection <type_t> containing the keys of the xtd::collections::generic::idictionary <key_t, value_t>.

Returns

An xtd::collections::generic::icollection <type_t> containing the keys of the object that implements xtd::collections::generic::idictionary <key_t, value_t>.

Remarks

The order of the keys in the returned xtd::collections::generic::icollection <type_t> is unspecified, but it is guaranteed to be the same order as the corresponding values in the xtd::collections::generic::icollection <type_t> returned by the xtd::collections::generic::idictionary::values property.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< intptr, item >, xtd::collections::generic::dictionary< key_type, mapped_type >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::dictionary< xtd::intptr, xtd::ptr< collection_type > >, xtd::collections::generic::dictionary< xtd::string, xtd::any_object >, xtd::collections::generic::dictionary< xtd::string, xtd::string >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

sync_root()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::sync_root ( ) const -> const xtd::object &

nodiscardpure virtualnoexcept

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 (const auto& item : my_collection) {
    // Insert your code here.
  }
}

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

values()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::values ( ) const -> value_collection

nodiscardpure virtualnoexcept

Gets an xtd::collections::generic::icollection <type_t> containing the values of the xtd::collections::generic::idictionary <key_t, value_t>.

Returns

An xtd::collections::generic::icollection <type_t> containing the values of the object that implements xtd::collections::generic::idictionary <key_t, value_t>.

Remarks

The order of the values in the returned xtd::collections::generic::icollection <type_t> is unspecified, but it is guaranteed to be the same order as the corresponding values in the xtd::collections::generic::icollection <type_t> returned by the xtd::collections::generic::idictionary::keys property.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< intptr, item >, xtd::collections::generic::dictionary< key_type, mapped_type >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::dictionary< xtd::intptr, xtd::ptr< collection_type > >, xtd::collections::generic::dictionary< xtd::string, xtd::any_object >, xtd::collections::generic::dictionary< xtd::string, xtd::string >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

add() [1/2]

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::add ( const xtd::collections::generic::key_value_pair< key_t, value_t > & item ) -> void

pure virtual

Adds an item to the xtd::collections::generic::icollection <type_t>.

Parameters

item	The object to add to the xtd::collections::generic::icollection <type_t>.

Exceptions

xtd::not_supported_exception

The xtd::collections::generic::icollection <type_t> is read-only.

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

add() [2/2]

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::add ( const key_t & key, const value_t & value ) -> void

pure virtual

Adds an element with the provided key and value to the xtd::collections::generic::idictionary <key_t, value_t>.

Parameters

key	The object to use as the key of the element to add.
value	The object to use as the value of the element to add.

Exceptions

xtd::argument_exception	An element with the same key already exists in the xtd::collections::generic::idictionary <key_t, value_t>.
xtd::not_supported_exception	The xtd::collections::generic::idictionary <key_t, value_t> is read-only.

Remarks

You can also use the operator [] to add new elements by setting the value of a key that does not exist in the dictionary; for example, my_collection["my_nonexistent_key"] = my_value. However, if the specified key already exists in the dictionary, setting the operator [] overwrites the old value. In contrast, the xtd::collections::generic::idictionary::add method does not modify existing elements.

Implementations can vary in how they determine equality of objects; for example, the xtd::collections::generic::list <type_t> class uses xtd::collections::generic::comparer::default_comparer, whereas the xtd::collections::generic::dictionary <key_t,value_t> class allows the user to specify the xtd::collections::generic::icomparer <type_t> implementation to use for comparing keys.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

clear()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::clear ( ) -> void

pure virtual

Removes all items from the xtd::collections::generic::icollection <type_t>.

Exceptions

xtd::not_supported_exception

The xtd::collections::generic::icollection <type_t> is read-only.

Remarks

xtd::collections::generic::icollection::count must be set to 0, and references to other objects from elements of the collection must be released.

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< intptr, item >, xtd::collections::generic::dictionary< key_type, mapped_type >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::dictionary< xtd::intptr, xtd::ptr< collection_type > >, xtd::collections::generic::dictionary< xtd::string, xtd::any_object >, xtd::collections::generic::dictionary< xtd::string, xtd::string >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

contains()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::contains ( const xtd::collections::generic::key_value_pair< key_t, value_t > & item ) const -> bool

nodiscardpure virtualnoexcept

Determines whether the xtd::collections::generic::icollection <type_t> contains a specific value.

Parameters

item	The object to locate in the xtd::collections::generic::icollection <type_t>.

Returns

true if item is found in the xtd::collections::generic::icollection <type_t>; otherwise, false.

Remarks

Implementations can vary in how they determine equality of objects; for example, xtd::collections::generic::list <type_t> uses xtd::collections::generic::compoarer <type_t>::default_comparer, whereas xtd::collections::generic::dictionary <key_t, value_t> allows the user to specify the xtd::collections::generic::icompoarer <type_t> implementation to use for comparing keys.

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

contains_key()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::contains_key ( const key_t & key ) const -> bool

nodiscardpure virtualnoexcept

Determines whether the xtd::collections::generic::idictionary <key_t, value_t> contains an element with the specified key.

Parameters

key	The key to locate in the xtd::collections::generic::idictionary <key_t, value_t>.

Returns

true if the xtd::collections::generic::idictionary <key_t, value_t> contains an element with the key; otherwise, false.

Remarks

Implementations can vary in how they determine equality of objects; for example, the xtd::collections::generic::list <type_t> class uses xtd::collections::generic::comparer <type_t>.Default, whereas the xtd::collections::generic::dictionary <key_t, value_t> class allows the user to specify the xtd::collections::generic::icomparer <type_t>x implementation to use for comparing keys.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

copy_to()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::copy_to ( xtd::array< xtd::collections::generic::key_value_pair< key_t, value_t > > & array, xtd::usize array_index ) const -> void

pure virtual

Copies the elements of the xtd::collections::generic::icollection <type_t> to an xtd::array, starting at a particular xtd::array index.

Parameters

array	The one-dimensional xtd::array that is the destination of the elements copied from xtd::collections::generic::icollection <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::generic::icollection <type_t> is greater than the available space from `array_index` to the end of the destination `array`.

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

get_enumerator()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::get_enumerator ( ) const -> xtd::collections::generic::enumerator< xtd::collections::generic::key_value_pair< key_t, value_t > >

nodiscardpure virtual

Returns an enumerator that iterates through a collection.

Returns

An xtd::collections::generic::enumerator object that can be used to iterate through the collection.

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< intptr, item >, xtd::collections::generic::dictionary< key_type, mapped_type >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::dictionary< xtd::intptr, xtd::ptr< collection_type > >, xtd::collections::generic::dictionary< xtd::string, xtd::any_object >, xtd::collections::generic::dictionary< xtd::string, xtd::string >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

remove() [1/2]

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::remove ( const xtd::collections::generic::key_value_pair< key_t, value_t > & item ) -> bool

pure virtual

Removes the first occurrence of a specific object from the xtd::collections::generic::icollection <type_t>.

Parameters

item	The object to remove from the xtd::collections::generic::icollection <type_t>.

Returns

true if item was successfully removed from the xtd::collections::generic::icollection <type_t>; otherwise, false. This method also returns false if item is not found in the original xtd::collections::generic::icollection <type_t>.

Exceptions

xtd::not_supported_exception

The xtd::collections::generic::icollection <type_t> is read-only.

Remarks

Implementations can vary in how they determine equality of objects; for example, xtd::collections::generic::list <type_t> uses xtd::collections::generic::compoarer <type_t>::default_comparer, whereas, xtd::collections::generic::dictionary <key_t, value_t> allows the user to specify the xtd::collections::generic::icompoarer <type_t> implementation to use for comparing keys.

In collections of contiguous elements, such as lists, the elements that follow the removed element move up to occupy the vacated spot. If the collection is indexed, the indexes of the elements that are moved are also updated. This behavior does not apply to collections where elements are conceptually grouped into buckets, such as a hash table.

Implements xtd::collections::generic::icollection< xtd::collections::generic::key_value_pair< key_t, value_t > >.

remove() [2/2]

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::remove ( const key_t & key ) -> bool

pure virtualnoexcept

Removes the element with the specified key from the xtd::collections::generic::idictionary <key_t, value_t>.

Parameters

key	The key of the element to remove.

Returns

true if the element is successfully removed; otherwise, false. This method also returns false if key was not found in the original xtd::collections::generic::idictionary <key_t, value_t>.

Remarks

Implementations can vary in how they determine equality of objects; for example, the xtd::collections::generic::list <type_t> class uses xtd::collections::generic::comparer <type_t>.Default, whereas the xtd::collections::generic::dictionary <key_t, value_t> class allows the user to specify the xtd::collections::generic::icomparer <type_t>x implementation to use for comparing keys.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

try_get_value()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::try_get_value ( const key_t & key, value_t & value ) const -> bool

nodiscardpure virtual

Gets the value associated with the specified key.

Parameters

key	The key whose value to get.
value	When this method returns, the value associated with the specified key, if the key is found; otherwise, the default value for the type of the value parameter.

Returns

true if the object that implements xtd::collections::generic::idictionary <key_t, value_t> contains an element with the specified key; otherwise, false.

Remarks

This method combines the functionality of the xtd::collections::generic::idictionary::contains_key method and the xtd::collections::generic::idictionary::operator [] property.

If the key is not found, then the value parameter gets the appropriate default value for the type value_t; for example, zero (0) for integer types, false for Boolean types, and null for reference types

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

operator[]()

template<typename key_t, typename value_t>

virtual auto xtd::collections::generic::idictionary< key_t, value_t >::operator[] ( const key_t & key ) -> value_t &

nodiscardpure virtual

Gets the element with the specified key.

Parameters

key	The key of the element to get.

Returns

The element with the specified key.

Exceptions

xtd::collections::generic::key_not_found_exception	The property is retrieved and key is not found.
xtd::not_supported_exception	The property is set and the xtd::collections::generic::idictionary <key_t, value_t> is read-only.

Remarks

This property provides the ability to access a specific element in the collection by using the following syntax: my_collection[key].

You can also use the operator [] to add new elements by setting the value of a key that does not exist in the dictionary; for example, my_collection["my_nonexistent_key"] = my_value. However, if the specified key already exists in the dictionary, setting the operator [] overwrites the old value. In contrast, the xtd::collections::generic::idictionary::add method does not modify existing elements. @remarks Implementations can vary in how they determine equality of objects; for example, the xtd::collections::generic::list <type_t> class uses xtd::collections::generic::comparer::default_comparer, whereas the xtd::collections::generic::dictionary <key_t,value_t> class allows the user to specify the xtd::collections::generic::icomparer <type_t> implementation to use for comparing keys. */ [[nodiscard]] virtual auto operator [](const key_t& key) const -> const value_t& = 0; /** @brief Sets the element with the specified key. @param key The key of the element to set. @return The element with the specified key. @exception xtd::collections::generic::key_not_found_exception The property is retrieved and key is not found. @exception xtd::not_supported_exception The property is set and the xtd::collections::generic::idictionary <key_t, value_t> is read-only. @remarks This property provides the ability to access a specific element in the collection by using the following syntax: my_collection[key]. @remarks You can also use the operator [] to add new elements by setting the value of a key that does not exist in the dictionary; for example, my_collection["my_nonexistent_key"] = my_value. However, if the specified key already exists in the dictionary, setting the operator []` overwrites the old value. In contrast, the xtd::collections::generic::idictionary::add method does not modify existing elements.

Implementations can vary in how they determine equality of objects; for example, the xtd::collections::generic::list <type_t> class uses xtd::collections::generic::comparer::default_comparer, whereas the xtd::collections::generic::dictionary <key_t,value_t> class allows the user to specify the xtd::collections::generic::icomparer <type_t> implementation to use for comparing keys.

Implemented in xtd::collections::generic::dictionary< key_t, value_t, hasher_t, equator_t, allocator_t >, xtd::collections::generic::dictionary< xtd::any_object, xtd::any_object >, xtd::collections::generic::ordered_dictionary< key_t, value_t, allocator_t >, and xtd::collections::generic::ordered_dictionary< xtd::any_object, xtd::any_object >.

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

• xtd.core/include/xtd/collections/generic/idictionary.hpp