Queue

Queue class

Queue class forward declaration.

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

Template parameters

ParameterDescription
TElement type.

Methods

MethodDescription
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() constGets iterator pointing to the first element (if any) of the const-qualified instance of the collection.
const_iterator cbegin() constGets iterator pointing to the first const-qualified element (if any) of the collection.
const_iterator cend() constGets 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&) constChecks if queue contains specific element using operator == to compare elements.
queue_t& data()Underlying data structure accessor.
const queue_t& data() constUnderlying 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() constGets 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 **) constFor internal purposes only.
virtual int get_Count() constGets number of elements in queue.
Detail::SmartPtrCounter * GetCounter()Gets reference counter data structure associated with the object.
IEnumeratorPtr GetEnumerator() overrideGets enumerator to iterate through the queue.
virtual int32_t GetHashCode() constAnalog of C# Object.GetHashCode() method. Enables hashing of custom objects.
virtual const TypeInfo& GetType() constGets actual type of object. Analog of C# System.Object.GetType() call.
virtual bool Is(const TypeInfo&) constCheck 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() constAnalog 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() constGets 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() constAnalog 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 overrideGets the implementation of begin const iterator for the current container.
System::Details::VirtualizedIteratorBase<T> * virtualizeBeginIterator() overrideGets the implementation of begin iterator for the current container.
System::Details::VirtualizedIteratorBase<T> * virtualizeEndConstIterator() const overrideGets the implementation of end const iterator for the current container.
System::Details::VirtualizedIteratorBase<T> * virtualizeEndIterator() overrideGets 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

TypedefDescription
ValueTypeThis type.
queue_tUnderlying data type.
IEnumerablePtrContainer of same type elements.
IEnumeratorPtrEnumerator 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
*/

See Also