queue library 의 queue class

Syntax

template <class Type, class Container = deque <Type>>
class queue

Constructor

queue();

explicit queue(const container_type& right);

• Example

int main(){
    queue<int> q;
}

Typedefs

Name	Description
container_type	queue의 container type
value_type	container에 저장되는 element type
size_type	element의 size를 표현하기 위한 unsigned int
reference	element의 reference type
const_reference	element의 const reference type

template <class _Tp, class _Container /*= deque<_Tp>*/>
class _LIBCPP_TEMPLATE_VIS queue
{
public:
    typedef _Container                               container_type;
    typedef typename container_type::value_type      value_type;
    typedef typename container_type::reference       reference;
    typedef typename container_type::const_reference const_reference;
    typedef typename container_type::size_type       size_type;
    
/**
*
*the rest is omitted
*/

}

Functions

empty

• queue가 비어있으면 true를 return

bool empty() const;

• Example

int main(){
    queue<int> q;

    if(q.empty()) cout<<"true";
}

push

• queue 의 맨 뒤에 val을 push

void push(const Type& val);
void push(const Type&& val);

pop

• queue 의 맨 앞 element 를 pop

void pop();

• Example

int main(){
    queue<int> q;
    int x=3;

    q.push(3); // void push(const Type&& val);
    q.push(x); // void push(const Type& val);

    q.pop();
    q.pop();

    if(q.empty()) cout<<"true";
}

front

• queue 의 맨 앞 element의 reference 를 return

reference front();

const_reference front() const;

back

• queue 의 맨 뒤 element의 reference 를 return

reference back();

const_reference back() const;

• Example

int main(){
    queue<int> q;
    int x=3;

    q.push(3);
    q.push(x);

    int& fr = q.front();
    int& br = q.back();

    int fv = q.front();
    int bv = q.back();

    q.front()++;
    fr++;

    if( fr==5 && fv==3 ) cout<<"true";
    
}

size

• queue의 element 개수를 return

size_type size() const;

• Example

int main(){
    queue<int> q;
    int x=3;

    q.push(3);
    q.push(x);
    int size = q.size();
    for(int i=0; i<size; i++){
        cout<<i<<" ";
    }
}

출처 : https://learn.microsoft.com/ko-kr/cpp/standard-library/queue-class?view=msvc-170