Why can't I add an item to my vector? - c++

Question

I have watched all tutorials and my steps are correct but I still can't get vector to work. Below is my main function.
int main(int argc, char* argv[]) {
std::vector list<test>;
list.push_back(new test());
}
I wish to add a custom custom class which is test. Header is below
#ifndef GIVE_ME_BRAIN_TEST_H
#define GIVE_ME_BRAIN_TEST_H
class test {
public:
test();
};
The class definition is below
#include "test.h"
test::test(){}
#endif //GIVE_ME_BRAIN_TEST_H
However, compiler keeps on spitting out this message.
Googling all suggests my code is correct. What am I doing wrong?

Answer 1

First, std::vector list<test> nerds to be declared as std::vector<test> list instead. That's actually why the compiler complains.
Second, std::vector<test> is a vector containing actual test objects. In your case, new test() returns a pointer to a test object. Your vector doesn't accept pointers to test objects.
Try this instead:
std::vector<test> list;
list.push_back(test());
Otherwise it will keep complaining.
Notice that new is not used anymore. As mentioned in the comments, do not forget that in C++ (unlike in Java, for example) every call to new has to be matched by a call to delete in order to avoid memory leaks. There is no automatic garbage collection. If you forget this, the compiler will not complain, but your program will use more and more memory and potentially (eventually) slow down your system and/or crash.

Answer 2

You wrote
std::vector list<test>;
But the correct syntax is
std::vector<test> list;
Also you can't add a pointer to the vector of objects. You need to dereference it:
auto tmp = new test();
list.push_back(*tmp);

Answer 3

First: Please add #include <vector>
Second: The line std::vector list<test>; need to be replaced with std::vector<test> list
Third: list.push_back take reference as parameter not pointer, so changed as follows:
test *tmp = new test();
list.push_back(*tmp);
The final solution is:
#include <iostream>
#include <vector>
using namespace std;
class test {
public:
test() {
}
};
int main(int argc, char* argv[]) {
std::vector<test> list;
test *tmp = new test();
list.push_back(*tmp);
}