C++ Handling super basic errors how should I do this? - c++

Question

double ctok(double c) // converts Celsius to Kelvin
{
if (c <= -273.15)
{
cout << "Temp too low.";
exit(1);
}
else {
double k = c + 273.15;
return k;
}
}
int main()
{
double c = 0;
cin >> c; // retrieve temperature to input variable
double k = ctok(c); // convecout << rt temperature
cout << k << '/n'; // print out temperature
}
So if c is smaller or equal to -273.15 I want to basically stop the program and I wanna do all this in the ctok function so I just check with an if statement and then use exit() but something here just seems off and I feel like this isn't a good way to handle it.. I've also heard using exit isn't really good but my only other idea is to handle this with exceptions:
So I add this function definition:
void error(string s)
{
throw runtime_error(s);
}
Then I can just do this:
double ctok(double c) // converts Celsius to Kelvin
{
if (c <= -273.15)
{
error("Temp too low.");
}
double k = c + 273.15;
return k;
}
int main()
{
try {
double c = 0;
cin >> c; // retrieve temperature to input variable
double k = ctok(c); // convecout << rt temperature
cout << k << '/n'; // print out temperature
}
catch (runtime_error a)
{
cout << a.what();
}
}
But this also feels a little overkill for handling such a simple error doesn't it? So I just wanna know is there like some good basic way to deal with such a basic error?

Answer 1

You could make ctok return bool and pass a pointer or reference to a variable and store the result:
bool ctok(double c, double *pr)
if( ! ctok( c, &k ) )
cout << "error\n";
or simply ctok() should throw itself the exception instead of a function that do nothing more than a throw...
IMO, both are simple solutions for a simple program, even with your 'error()' function.