I keep receiving the following two errors and I can't figure out why.
error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup MSVCRTD.lib(crtexe.obj)
error LNK1120: 1 unresolved externals
Ensuring that I run it as Console [even in Linker Properties it says Console] I am using VC++ 2012 Ultimate. I'm not insanely technically oriented with jargon and advanced concepts so please try not to overwhelm me Dx.
//Main.cpp
#include <conio.h>
#include "XArray.h"
int Main() {
XArray<int> Test;
Test.Add(3);
getch();
return 1;
}
Followed by.
#ifndef XARRAY_H
#define XARRAY_H
template <class X>
class XIndex {
public:
X Value;
XIndex<X> *Next;
//Construct
XIndex(X ArrayValue) { Value = ArrayValue; Next = nullptr; }
};
template <class X>
class XArray {
XIndex<X> *First;
public:
//Construct/Destruct;
XArray() { First = nullptr; }
~XArray();
//Operators that Alter the structure;
void Add(X); //Add X to the end.
void AddX(X, int); //Create Int amount of X values
void Insert(int, X); //Insert X at Index int
bool Remove(int); //Remove Index int. Return true if deleted, false if failed.
//void Sort(); //Todo -- Sorts by value.
//Operators that deal with the values.
X Get(int);
void Set(int, X);
};
template <class X>
void XArray<X>::AddX(X NewVal, int Quantity) {
for (int i = 0; i < Quantity; i++)
Add(NewVal);
}
template <class X>
void XArray<X>::Add(X NewVal) {
XIndex<X> *CurrentIndex;
XIndex<X> *NewNode; //Where we store NewVal
NewNode = new XIndex<X>(NewVal);
//List doesn't exist.
if (!First) {
First = NewNode;
} else {
//Start at beginning.
CurrentIndex = First;
while ((*CurrentIndex).Next){
CurrentIndex = (*CurrentIndex).Next;
}
(*CurrentIndex).Next = NewNode;
}
}
template <class X>
void XArray<X>::Insert(int Index, X NewVal) {
XIndex<X> *CurrentIndex;
XIndex<X> *PrevIndex;
XIndex<X> *NewNode; //Where we store NewVal
iCounter = 0;
NewNode = new XIndex<X>(NewVal);
//List doesn't exist.
if (!First) {
First = NewNode;
} else {
//Start at beginning.
CurrentIndex = First;
while ((*CurrentIndex).Next != nullptr && iCounter < Index){
iCounter += 1
PrevIndex = CurrentIndex;
CurrentIndex = (*CurrentIndex).Next;
}
if (PreviousNode == nullptr) {
First = NewNode;
(*NewNode).Next = CurrentIndex;
} else {
(*PrevIndex).Next = NewNode;
(*NewNode).Next = CurrentIndex;
}
}
}
template <class X>
bool XArray<X>::Remove(int Index) {
XIndex<X> *CurrentIndex;
XIndex<X> *PrevIndex;
int iCounter = 0;
if (First == nullptr) return false; //We never had a list.
//It's the first one;
if (Index == 0) {
CurrentIndex = (*First).Next;
delete First;
First = CurrentIndex;
return true;
}
//Starting as normal.
CurrentIndex = First;
//Loop until we reach the index.
while (CurrentIndex != nullptr && iCounter < Index) {
iCounter += 1
PrevIndex = CurrentIndex;
CurrentIndex = (*CurrentIndex).Next;
}
if (CurrentIndex != nullptr) {
(*PrevIndex).Next = (*CurrentIndex).Next;
delete CurrentIndex;
return true;
}
return false;
}
//Destructor;
template <class X>
XArray<X>::~XArray() {
XIndex<X> *NextIndex;
XIndex<X> *CurrentIndex;
//Start at beginning.
CurrentIndex = First;
//So long as we aren't at the end [when Next = nullptr];
while (CurrentIndex != nullptr) {
NextIndex = (*CurrentIndex).Next;
delete CurrentIndex;
CurrentIndex = NextIndex;
}
}
#endif
In C++ main function is declared as int main()
or int main(int argc, char *argv[])
(see C++ Standard, paragraph 3.6.1 Main function).
In your case linker can't find the body of main
, so it throws an error.