Queue

Queue class

Queue class forward declaration.

template<typename T>class Queue : public System::Collections::Generic::IEnumerable<T>

Template parameters

Parameter	Description
T	Element type.

Methods

Method	Description
iterator begin()	Gets iterator pointing to the first element (if any) of the collection. This iterator can’t be used to change a referenced object because GetEnumerator() returns a copy-object of T.
const_iterator begin() const	Gets iterator pointing to the first element (if any) of the const-qualified instance of the collection.
const_iterator cbegin() const	Gets iterator pointing to the first const-qualified element (if any) of the collection.
const_iterator cend() const	Gets iterator pointing right after the last const-qualified element (if any) of the collection.
virtual void Clear()	Deletes all elements in queue.
virtual bool Contains(const T&) const	Checks if queue contains specific element using operator == to compare elements.
queue_t& data()	Underlying data structure accessor.
const queue_t& data() const	Underlying data structure accessor.
T Dequeue()	Gets item from the beginning of the queue.
iterator end()	Gets iterator pointing right after the last element (if any) of the collection. This iterator can’t be used to change a referenced object because GetEnumerator() returns a copy-object of T.
const_iterator end() const	Gets iterator pointing right after the last element (if any) of the const-qualified instance of the collection.
void Enqueue(const T&)	Puts item to the end of the queue.
virtual bool Equals(ptr)	Compares objects using C# Object.Equals semantics.
static std::enable_if<IsSmartPtr<T1>::value&&IsSmartPtr<T2>::value, bool>::type Equals(T1 const&, T2 const&)	Compares reference type objects in C# style.
static std::enable_if<!IsSmartPtr<T1>::value&&!IsSmartPtr<T2>::value, bool>::type Equals(T1 const&, T2 const&)	Compares value type objects in C# style.
static bool Equals(float const&, float const&)	Emulates C#-style floating point comparison where two NaNs are considered equal even though according to IEC 60559:1989 NaN is not equal to any value, including NaN.
static bool Equals(double const&, double const&)	Emulates C#-style floating point comparison where two NaNs are considered equal even though according to IEC 60559:1989 NaN is not equal to any value, including NaN.
virtual bool FastCast(const Details::FastRttiBase&, void **) const	For internal purposes only.
virtual int get_Count() const	Gets number of elements in queue.
Detail::SmartPtrCounter * GetCounter()	Gets reference counter data structure associated with the object.
IEnumeratorPtr GetEnumerator() override	Gets enumerator to iterate through the queue.
virtual int32_t GetHashCode() const	Analog of C# Object.GetHashCode() method. Enables hashing of custom objects.
virtual const TypeInfo& GetType() const	Gets actual type of object. Analog of C# System.Object.GetType() call.
virtual bool Is(const TypeInfo&) const	Check if object represents an instance of type described by targetType. Analog of C# ‘is’ operator.
bool LINQ_All(std::function<bool(T)>)	Determines whether all elements of a sequence satisfy a condition.
bool LINQ_Any()	Determines whether a sequence contains any elements.
bool LINQ_Any(std::function<bool(T)>)	Determines whether any element of a sequence exists or satisfies a condition.
SharedPtr<IEnumerable<ResultType>> LINQ_Cast()	Casts the elements to the specified type.
SharedPtr<IEnumerable<Result>> LINQ_Cast()
SharedPtr<IEnumerable<T>> LINQ_Concat(SharedPtr<IEnumerable<T>>)	Concatenates two sequences.
bool LINQ_Contains(T)	Determines if a sequence contains a specified value.
int LINQ_Count()	Returns the number of elements in the sequence (calculated via direct counting).
int LINQ_Count(const Func<T, bool>&)	Returns the number of elements in the sequence that satisfy the specified condition.
T LINQ_ElementAt(int)	Returns the element at a specified index in a sequence.
T LINQ_First()	Returns the first element of a sequence.
T LINQ_First(const Func<T, bool>&)	Returns the first element of a sequence that satisfy the specified condition.
T LINQ_FirstOrDefault()	Returns the first element of a sequence, or a default value if the sequence is empty.
T LINQ_FirstOrDefault(std::function<bool(T)>)	Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.
System::SharedPtr<IEnumerable<System::SharedPtr<System::Linq::IGrouping<Key, T>>>> LINQ_GroupBy(System::Func<T, Key>)	Groups the elements of a sequence.
SharedPtr<IEnumerable<SharedPtr<System::Linq::IGrouping<Key, Source>>>> LINQ_GroupBy(System::Func<Source, Key>)
T LINQ_Last()	Returns the last element of a sequence.
T LINQ_LastOrDefault()	Returns the last element of a sequence, or a default value if the sequence is empty.
SharedPtr<IEnumerable<ResultType>> LINQ_OfType()	Filters the elements of the sequence based on the specified type.
SharedPtr<IEnumerable<Result>> LINQ_OfType()
SharedPtr<IEnumerable<T>> LINQ_OrderBy(const Func<T, Key>&)	Sorts the elements of a sequence in ascending order according to the key values selected by keySelector.
SharedPtr<IEnumerable<Source>> LINQ_OrderBy(const Func<Source, Key>&)
SharedPtr<IEnumerable<T>> LINQ_OrderByDescending(const Func<T, Key>&)	Sorts the elements of a sequence in descending order according to the key values selected by keySelector.
SharedPtr<IEnumerable<Source>> LINQ_OrderByDescending(const Func<Source, Key>&)
SharedPtr<IEnumerable<ResultType>> LINQ_Select(const Func<T, ResultType>&)	Transforms elements of a sequence.
SharedPtr<IEnumerable<ResultType>> LINQ_Select(const Func<T, int32_t, ResultType>&)	Transforms each element of a sequence into a new form by incorporating the element’s index.
SharedPtr<IEnumerable<Result>> LINQ_Select(const Func<Source, Result>&)
SharedPtr<IEnumerable<Result>> LINQ_Select(const Func<Source, int32_t, Result>&)
SharedPtr<IEnumerable<ResultType>> LINQ_SelectMany(const Func<T, SharedPtr<IEnumerable<ResultType>>>&)	Projects each element of a sequence and combines the resulting sequences into one sequence.
SharedPtr<IEnumerable<Result>> LINQ_SelectMany(const Func<Source, SharedPtr<IEnumerable<Result>>>&)
System::ArrayPtr<T> LINQ_ToArray()	Creates an array from a sequence.
SharedPtr<List<T>> LINQ_ToList()	Creates a List from a sequence.
SharedPtr<IEnumerable<T>> LINQ_Where(std::function<bool(T)>)	Filters a sequence based on the specified predicate.
void Lock()	Implements C# lock() statement locking. Call directly or use LockContext sentry object.
virtual ptr MemberwiseClone() const	Analog of C# Object.MemberwiseClone() method. Enables cloning custom types.
Object()	Creates object. Initializes all internal data structures.
Object(Object const&)	Copy constructor. Doesn’t copy anything, really, just initializes new object and enables copy constructing subclasses.
Object& operator=(Object const&)	Assignment operator. Doesn’t copy anything, really, just initializes new object and enables copy constructing subclasses.
T Peek()	Gets item from the beginning of the queue, but does not remove it from queue.
Queue()	Constructs empty queue.
Queue(int)	Constructs empty queue.
Queue(const SharedPtr<IEnumerable<T>>&)	Copy constructor.
static bool ReferenceEquals(ptr const&, ptr const&)	Compares objects by reference.
static std::enable_if<!IsSmartPtr<T>::value, bool>::type ReferenceEquals(T const&, T const&)	Compares objects by reference.
static std::enable_if<!IsSmartPtr<T>::value, bool>::type ReferenceEquals(T const&, std::nullptr_t)	Reference-compares value type object with nullptr.
bool ReferenceEquals(String const&, std::nullptr_t)	Specialization of Object::ReferenceEquals for case of string and nullptr.
bool ReferenceEquals(String const&, String const&)	Specialization of Object::ReferenceEquals for case of strings.
int RemovedSharedRefs(int)	Decreases shared reference count by specified value.
virtual void SetTemplateWeakPtr(uint32_t)	Set n’th template argument a weak pointer (rather than shared). Allows switching pointers in containers to weak mode.
int SharedCount() const	Gets current value of shared reference counter.
Object * SharedRefAdded()	Increments shared reference count. Shouldn’t be called directly; instead, use smart pointers or ThisProtector.
int SharedRefRemovedSafe()	Decrements and returns shared reference count. Shouldn’t be called directly; instead, use smart pointers or ThisProtector.
virtual String ToString() const	Analog of C# Object.ToString() method. Enables converting custom objects to string.
static const TypeInfo& Type()	Implements C# typeof(System.Object) construct.
void Unlock()	Implements C# lock() statement unlocking. Call directly or use LockContext sentry object.
System::Details::VirtualizedIteratorBase<T> * virtualizeBeginConstIterator() const override	Gets the implementation of begin const iterator for the current container.
System::Details::VirtualizedIteratorBase<T> * virtualizeBeginIterator() override	Gets the implementation of begin iterator for the current container.
System::Details::VirtualizedIteratorBase<T> * virtualizeEndConstIterator() const override	Gets the implementation of end const iterator for the current container.
System::Details::VirtualizedIteratorBase<T> * virtualizeEndIterator() override	Gets the implementation of end iterator for the current container.
Detail::SmartPtrCounter * WeakRefAdded()	Increments weak reference count. Shouldn’t be called directly; instead, use smart pointers or ThisProtector.
void WeakRefRemoved()	Decrements weak reference count. Shouldn’t be called directly; instead, use smart pointers or ThisProtector.
virtual ~Object()	Destroys object. Frees all internal data structures.

Typedefs

Typedef	Description
ValueType	This type.
queue_t	Underlying data type.
IEnumerablePtr	Container of same type elements.
IEnumeratorPtr	Enumerator type.

Remarks

Queue container wrapping STL list. Objects of this class should only be allocated using System::MakeObject() function. Never create instance of this type on stack or using operator new, as it will result in runtime errors and/or assertion faults. Always wrap this class into System::SmartPtr pointer and use this pointer to pass it to functions as argument.

#include <system/collections/queue.h>
#include <system/smart_ptr.h>

using namespace System;
using namespace System::Collections::Generic;

void PrintItems(const SmartPtr<IEnumerable<int>> &queue)
{
  for (const int item: queue)
  {
    std::cout << item << ' ';
  }
  std::cout << std::endl;
}

int main()
{
  // Create the Queue-class instance.
  auto queue = MakeObject<Queue<int>>();

  // Fill the queue.
  queue->Enqueue(1);
  queue->Enqueue(2);
  queue->Enqueue(3);

  // Print the first queue item. The Peek method doesn't remove an item from the queue.
  std::cout << queue->Peek() << std::endl;
  // Print the queue items.
  PrintItems(queue);

  // Print the first queue item. The Dequeue method removes an item from the queue.
  std::cout << queue->Dequeue() << std::endl;
  // Print the queue items.
  PrintItems(queue);

  return 0;
}
/*
This code example produces the following output:
1
1 2 3
1
2 3
*/