you can use exception handling mechanism:
#include <stdexcept>
std::string y = "2323298347293874928374927392374924"
int x;
try {
x = stoi(y);
}
catch(std::invalid_argument& e){
// if no conversion could be performed
}
catch(std::out_of_range& e){
// if the converted value would fall out of the range of the result type
// or if the underlying function (std::strtol or std::strtoull) sets errno
// to ERANGE.
}
catch(...) {
// everything else
}
detailed description of stoi function and how to handle errors