xtd::collections::generic::enumerator<> Struct Reference

Inheritance diagram for xtd::collections::generic::enumerator<>:

Definition

Supports a simple iteration over a generic collection.

Definition

template<typename type_t>
class enumerator static_

Header

#include <xtd/collections/generic/enumerator>

Namespace

xtd::collections::generic

Library

xtd.core

Remarks

The xtd::collections::generic::enumerator <type_t> class is used to encapsulate an xtd::collections::generic::ienumerator <type_t>.

Public Static Methods
template<typename collection_t, typename version_t = std::nullptr_t>
static auto	create (const collection_t &items, const version_t *current_version=nullptr) noexcept
	Create an enumerator from specified collection and version.

Public Constructors
	enumerator ()=default
	Initializes a new instance of the xtd::collections::generic::enumerator <type_t> class.

Public Properties
const type_t &	current () const override
	Gets the element in the collection at the current position of the enumerator.

Public Methods
bool	move_next () override
	Advances the enumerator to the next element of the collection.
void	reset () override
	Sets the enumerator to its initial position, which is before the first element in the collection.

Additional Inherited Members
	object ()=default
	Create a new instance of the ultimate base class object.
virtual auto	equals (const object &obj) const noexcept -> bool
	Determines whether the specified object is equal to the current object.
virtual auto	get_hash_code () const noexcept -> xtd::usize
	Serves as a hash function for a particular type.
virtual auto	get_type () const noexcept -> type_object
	Gets the type of the current instance.
template<typename object_t>
auto	memberwise_clone () const -> xtd::unique_ptr_object< object_t >
	Creates a shallow copy of the current object.
virtual auto	to_string () const -> xtd::string
	Returns a xtd::string that represents the current object.
template<typename object_a_t, typename object_b_t>
static auto	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept -> bool
	Determines whether the specified object instances are considered equal.
template<typename object_a_t, typename object_b_t>
static auto	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept -> bool
	Determines whether the specified object instances are the same instance.

Constructor & Destructor Documentation

enumerator()

xtd::collections::generic::enumerator< type_t >::enumerator ( )

default

Initializes a new instance of the xtd::collections::generic::enumerator <type_t> class.

Member Function Documentation

create()

template<typename collection_t, typename version_t = std::nullptr_t>

auto xtd::collections::generic::enumerator<>::create ( const collection_t & items, const version_t * current_version = nullptr )

inlinestaticnoexcept

Create an enumerator from specified collection and version.

Template Parameters

collection_t	The collection type.
version_t	The collection version type.

Parameters

items	The collection to create an enumerator on.
current_version	A pointer on the collection current version.

Returns

The enumerator created.

Examples

The following code shows how to use enumerator<>::create method to create a simple enumerator on any std or xtd collections.

#include <xtd/xtd>
 
class program {
public:
  static auto main() -> void {
    auto boxes = box_collection {{10, 20, 30}, {20, 5, 10}, {12, 3, 7}};
    
    auto enumerator = boxes.get_enumerator();
    while (enumerator.move_next())
      console::write_line(enumerator.current().to_string());
    
    console::write_line();
    for (auto box : boxes)
      console::write_line(box.to_string());
    
    console::write_line();
    for (auto iterator = boxes.begin(); iterator != boxes.end(); ++iterator)
      console::write_line(iterator->to_string());
  }
 
  struct box : public iequatable<program::box> {
    box() = default;
    box(int l, int w, int h) : length{l}, width {w}, height {h} {}
    
    int length = 0;
    int width = 0;
    int height = 0;
    
    bool equals(const program::box& o) const noexcept override {return length == o.length && width == o.width && height == o.height;}
    string to_string() const noexcept {return string::format("box [length={}, width={}, height={}]", length, width, height);}
  };
  
  class box_collection : public ienumerable<program::box> {
  public:
    box_collection(const std::initializer_list<program::box>& boxes) : boxes_(boxes) {}
    
    enumerator<program::box> get_enumerator() const override {
      return enumerator<>::create(boxes_);
    }
    
  private:
    list<program::box> boxes_;
  };
};
 
startup_(program::main);
 
// This code produces the following output :
//
// box [length=10, width=20, height=30]
// box [length=20, width=5, height=10]
// box [length=12, width=3, height=7]
//
// box [length=10, width=20, height=30]
// box [length=20, width=5, height=10]
// box [length=12, width=3, height=7]
//
// box [length=10, width=20, height=30]
// box [length=20, width=5, height=10]
// box [length=12, width=3, height=7]

current()

const type_t & xtd::collections::generic::enumerator< type_t >::current ( ) const

inlinenodiscardoverridevirtual

Gets the element in the collection at the current position of the enumerator.

Returns

The element in the collection at the current position of the enumerator.

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

move_next()

bool xtd::collections::generic::enumerator< type_t >::move_next ( )

inlinenodiscardoverridevirtual

Advances the enumerator to the next element of the collection.

Returns

true if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of the collection.

Exceptions

xtd::invalid_operation_exception

The collection was modified after the enumerator was created.

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

reset()

void xtd::collections::generic::enumerator< type_t >::reset ( )

inlineoverridevirtual

Sets the enumerator to its initial position, which is before the first element in the collection.

Exceptions

xtd::invalid_operation_exception	The collection was modified after the enumerator was created.
xtd::not_supported_exception	The enumerator does not support being reset.

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

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

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