Variable length input to char array?

[MarketAnarchist]

*std::string is not an option*

How do I allow the user to pass input to an array of characters where the length of that input can vary?

I have something like this.

#include <iostream>

using namespace std;

int main(int argc, char* argv[])
{
	char a[12];
        for (int i = 0; i < 12; i++) {
		cin >> a[i];
	}
        return 0;
}

however this requires that the user provide 12 characters before it will continue on with the program. i want it to be so that if the user enters three characters, it will assign those 3 characters to the first three elements in the array and then move on with the program.

as a bonus that would be ideal but not necessary is if there was a way to set the length of the array to the total number of characters input.

thanks to everyone who takes a look!

[abhishekm71]

You should use std::vector. New elements can be added dynamically.

Ofcourse, you will still need a way to terminate the for loop, maybe by first reading the length of the input.

[MarketAnarchist]

vector is also not an option. i need to make the memory that is holding this information thread safe and i cant do std::atomic<std::vector>. i could take the input and hold it in a vector temporarily and then transfer it over to a char array with

for (int i = 0; i < vector.size(); ++i) {}

or something similar with string and ill do that if no one else has any suggestions but im still really interested if there is a more direct way to do this.

[D80DSL3A]

no reply

[mxood]

ok im sorry if this is not what you were asking but here is a messed up code.
new to c++, but i know some of this not good coding practice for sure, but might spring up an idea. hope it helps,

	string strOne;
	cin >> strOne;
	string::size_type count = strOne.size();
	char *x = new char[count](); 
	for (int i = 0; i < count; i++){
		x[i] = strOne.at(i);
	}
	for (int i = 0; i < count; i++){
		cout << x[i];
	}