Считать строку с консоли

#include <iostream>
 
using namespace std;
 
int main()
{
   char *str = new char;
   cin>>str;
   cout << str << endl; 
   delete [] str;
   return 0;
}

return answer == 'y';

char* GetString()
{
    char* str = new char;
    size_t length = 1;
    while ((str[length - 1] = getchar()) != '\n')
    {
        char* tmp = new char[length];
        memcpy(tmp, str, length);
        delete[] str;
        str = new char[length + 1];
        memcpy(str, tmp, length++);
        delete[] tmp;
    }
    str[length - 1] = 0;
    return str;
}

std::istream& in = std::cin;
char tmp;
while(in.get(tmp))
{
    //......
}

#include <iostream>
#include <fstream>
 
void outputChar(std::istream& in)
{
    char tmp;
    while(in.get(tmp) && tmp != '\n')
        std::cout << tmp << std::endl;
    std::cout << "End of line" << std::endl;
}
int main(int argc, char *argv[])
{
    std::istream& console = std::cin;
    std::fstream file("./file.txt");
    
    outputChar(file);
    outputChar(console);
    
    file.close();
}

char* GetString(istream& stream)
{
    char* str = new char;
    size_t length = 1;
    while ((stream.get(str[length - 1])) && (str[length - 1] != '\n'))
    {
        char* tmp = new char[length];
        memcpy(tmp, str, length);
        delete[] str;
        str = new char[length + 1];
        memcpy(str, tmp, length++);
        delete[] tmp;
    }
    str[length - 1] = 0;
    return str;
}