我包括<iterator>但得到未知的类型名称“迭代器”

Question

I feel like this has to be an issue with namespace pollution, otherwise I dont know my compiler thinks iterator is an unknown type name

In a previous coding project I had a class with the exact same method declaration with no issues, which is why I dont understand why it doesnt work here.

The full error is

In file included from AlgoContainer.cc:1:
./AlgoContainer.h:14:3: fatal error: unknown type name 'iterator'
            iterator begin() const;
            ^

1 error generated.

Below is the code where the error is being thrown, in my header file

#ifndef AlgoContainer_H_INCLUDED
#define AlgoContainer_H_INCLUDED

#include <vector>
#include "Task.h"
#include <iterator>


class AlgoContainer{
    public:
        AlgoContainer() = default;
        void addTask(const Task);
        ~AlgoContainer();
        iterator begin() const;
        iterator end() const;

    private:
        std::vector<Task> allTasks;
        void sort();
    
 };

 #endif /*AlgoContainer_H_INCLUDED*/

If it is needed I will include the Task header file I am using and the AlgoContainer.cc files

AlgoContainer.cc

#include "AlgoContainer.h"

using namespaces std;

AlgoContainer::addTask(const Task newTask){
    this->allTasks.push_back(newTask);
}

AlgoContainer::~AlgoContainer(){
    //TODO delete without memory leak
}

AlgoContainer::iterator AlgoContainer::begin() const{
    return this->allTasks.begin();
}

AlgoContainer::iterator AlgoContainer::end() const{
    return this->allTasks.end();
}

void AlgoContainer::sort(){
    //TODO
}

Task.h

#ifndef Task_H_INCLUDED
#define Task_H_INCLUDED

class Task{
    public:
        Task(int pid, int arrivalTime, int burstDuration, int priority = 1);
        ~Task() = default;
        void alterBurstDuration(const int);
        int getPriority();
        int getPid();
        int getArrivalTime();
        int getBurstDuration();
        void continueWaiting();
        void taskComplete(const int);
    private:
        int pid;
        int arrivalTime;
        int burstDuration;
        int priority;
        int waitingTime;
        int finishedTime;
        enum state { waiting, running, finished};
        state taskState;
};

#endif /*TASK_H_INCLUDED*/

Additionally these are the parameters in which I am compiling if that helps

CXX=g++
CXXFLAGS=-Wall -Wextra -Wpedantic -Werror -Wfatal-errors -Winit-self -Wshadow -Wcomment -Wctor-dtor-privacy -Wold-style-cast -D_GLIBCXX_DEBUG -fno-diagnostics-show-option -std=c++14

Adding an std::iterator compiles with an error of

./AlgoContainer.h:14:8: fatal error: use of class template     'std::iterator' requires template
  arguments
            std::iterator begin() const;

Again weirdly in my past project I did not have the std:: before the iterator and had no issues, without using namespace std in the header

Answer 1

I was able to solve this by changing my header file to be

class AlgoContainer{
private:
    std::vector<Task> allTasks;
    void sort();
public:
    AlgoContainer() = default;
    void addTask(const Task);
    ~AlgoContainer();
    //CHANGE HERE
    using iterator = decltype(allTasks)::const_iterator;
    iterator begin() const;
    iterator end() const;

};

What is the consensus on whether this is frowned upon or not?