calc.min.c

#include <iostream>using namespace std;
inline bool isInteger(const std::string & s){   if(s.empty() || ((!isdigit(s[0])) && (s[0] != '-') && (s[0] != '+'))) return false ;
   char * p ;   strtol(s.c_str(), &p, 10) ;
   return (*p == 0) ;}
int main() { string from, to, disp, v; int value; bool a = true;  cout << "What would you like to convert from?" << endl << ">>"; cin >> from; cout << "What would you like to convert to?" << endl << ">>"; cin >> to; cout << "Calculator:" << endl << ">>";  disp = to == "C" ? "Celsius" : to == "F" ? "Fahrenheit" : to == "K" ? "Kelvin" : "N/A";  while (a) {  cin >> v;  if (!isInteger(v)) {   a = false;  } else {   value << (int)v.front();//ERRORS   if (from == "F") {    value = (value - 32)/1.8;   } else if (from == "K") {    value -= 273;   }   if (to == "F") {    value = value * 1.8 + 32;   } else if (to == "K") {    value += 273;   }   cout << value << " degrees " << disp << endl << ">>";  } } a = true;}