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

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

Definition

Supports a simple iteration over a generic collection.

Definition

template<class type_t>
class enumerator interface_

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<class collection_t, class vertion_t = std::nullptr_t>
static auto	create (const collection_t &items, const vertion_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.
	enumerator (ptr< ienumerator< type_t > > enumerator)
	Initializes a new instance of the xtd::collections::generic::enumerator <type_t> class with specified enumerator.

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

Constructor & Destructor Documentation

enumerator() [1/2]

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

default

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

enumerator() [2/2]

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

inline

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

Parameters

enumerator

The xtd::collections::generic::ienumerator <type_t> enumerator to encapsulate.

Member Function Documentation

create()

template<class collection_t, class vertion_t = std::nullptr_t>

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

inlinestaticnoexcept

Create an enumerator from specified collection and version.

Template Parameters

collection_t	The collection type.
vertion_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>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
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

inlineoverridevirtual

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 ( )

inlineoverridevirtual

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