C++ Partial Specialization Cannot Match Argument List for Primary Template

Question

I'm getting an error code C2753 -- 'HashTable: Partial Specialization Cannot Match Argument List for Primary Template -- when I try to build my project.

My HashTable.h file:

#pragma once  //should prevent error C2953..... 'HashTable': class template has already been defined. https://stackoverflow.com/questions/10157416/error-class-template-has-already-been-defined
#include <string>
#include <iostream>
#include <iomanip>
#include "Record.h"

using namespace std;

/*Create a closed hash HashTable using Double Hashing & Templates and does not allow duplicates.*/
template <class T>
class HashTable<T> {
private:
    int numItems;
    int hashSize;
    Record<T> *hashArray;
    int hashOne(int) const;
    int hashTwo(int) const;

public:
    /*TEMPLATE*/
    HashTable();
    ~HashTable();
    bool insert(int, T, int&);
    bool remove(int);
    bool find(int, T&);
    float alpha();
    int getNumItems();
    int getSize();
    bool print();

/*Source:  Partial Code for Overriding print method from StackOverflow.com*/
ostream& print(ostream& os) const {
    os << "-----------------------------------------------------------------------" << endl;
    os << "Hash Table Slot #|" << setw(20) << "Key and Value" << setw(12) << "" << endl;
    os << "-----------------------------------------------------------------------" << endl;
    for (int i = 0; i < hashSize; i++)
    {
        os << setw(10) << i << setw(8) << "|";
        if (hashArray[i].isEmpty())
            os << setw(16) << hashArray[i] << setw(14) << "" << endl;
        else if (hashArray[i].isTombstone())
            os << setw(20) << hashArray[i] << setw(12) << "" << endl;
        else
            os << setw(12) << hashArray[i] << endl;
    }
    os << "-----------------------------------------------------------------------" << endl;
    return os;
    }
};  //End of HashTable Class

/*Constructor of the HashTable.
Initializes the size to 1000 and numItems to 0.
Loop to fill hashArray with empty records.*/
template <class T>
HashTable<T>::HashTable() {
    this->hashSize = 1000;
    this->numItems = 0;
    hashArray = new Record<T>[hashSize];
    for (int i = 0; i < hashSize; i++) {
        hashArray[i] = Record<T>();
    }
}  //end of Constructor

/*Deconstructor for HashTable.  Deletes hashArray.*/
template <class T>
HashTable<T>::~HashTable() {
    delete[] hashArray;
}  //end of Deconstructor

/*Insert a new key/value pair into the HashTable, duplicates not allowed.
If added return true, return the numver of collisions in int& collisions,and increment numItems.
Otherwise return false.*/
template<class T>
bool HashTable<T>::insert(int key, T value, int& collisions) {
    if (numItems >= hashSize) {
        cout << "HashArray FULL!" << endl;
        return false;
    }
    if (hashArray[hashOne(key)].isNormal()) {
        int loc = 0;
        if (hashArray[(hashOne(key) + loc) % hashSize].getKey() == key) {
            return false;
    }
    while (hashArray[(hashOne(key) + loc) % hashSize].isNormal()) {
        collisions++;
        loc = loc + hashTwo(key);
            if (hashArray[(hashOne(key) + loc) % hashSize].getKey() == key) {
                return false;
            }
        }
        hashArray[(hashOne(key) + loc) % hashSize] = Record<T>(key, value);
        numItems++;
        return true;
    }
    else {
        hashArray[hashOne(key)] = Record<T>(key, value);
        numItems++;
        return true;
    }
    return false;
}  //end insert method

//...other methods go here...//
//hashOne & hashTwo functions are my last two functions, if that matters.

My .cpp file is really just bare bones, but here it is:

#include "stdafx.h"
#include "HashTable.h"

int main() {
    return 0;
}

I am using Visual Studio 2015 & have already looked Here, here, here, and here trying to find a solution, along with numerous other sources from Google and cplusplus.com, but none of these have solved my problem.

Any help or advice will be greatly appreciated!

@aschepler on the line ending the HastTable class that reads "}; //End of HashTable Class" — Ra'kiir, Apr 20 '17 at 00:42
@Jarod42 oh okay that's good to know. Does using it cause problems or is it just a convention thing? — Ra'kiir, Apr 20 '17 at 00:43
See [why-is-using-namespace-std-considered-bad-practice](http://stackoverflow.com/questions/1452721/why-is-using-namespace-std-considered-bad-practice) — Jarod42, Apr 20 '17 at 01:01

score 0 · Answer 1 · answered Apr 19 '17 at 22:04

0

template <class T>
class HashTable<T> {

should be

template <class T>
class HashTable {

You don't put an argument list after the class name when defining the primary class template, only when defining a specialization.

answered Apr 19 '17 at 22:04

aschepler

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Hmmm but that gives me two new errors: (1) "Class Template Has Already Been Defined" error on the end of the HashTable class & (2) "Unable to Match Function Definition to an Existing Declaration" on the constructor, destructor, and each method. – Ra'kiir Apr 20 '17 at 00:41

C++ Partial Specialization Cannot Match Argument List for Primary Template

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