(C++) IsInt

 

IsInt is a checking code snippet to check if a std::string can be converted to an integer.

 

CanCast and CanLexicalCast are more general versions of IsInt.

Technical facts

 

Operating system(s) or programming environment(s)

• Lubuntu 15.04 (vivid)

IDE(s):

• Qt Creator 3.1.1

Project type:

• Console application

C++ standard:

• C++98

Compiler(s):

• G++ 4.9.2

Libraries used:

• STL: GNU ISO C++ Library, version 4.9.2

 

 

 

 

 

Qt project file: ./CppIsInt/CppIsInt.pro

 

---

include(../../ConsoleApplication.pri) include(../../Libraries/Boost.pri) SOURCES += main.cpp

 

 

 

 

 

./CppIsInt/main.cpp

 

---

#include <sstream> ///IsInt determines if std::string can be converted to integer. ///From http://www.richelbilderbeek.nl/CppIsInt.htm bool IsIntStl(const std::string& s) {   std::istringstream i(s);   int temp{0};   i >> temp;   if (!i) return false;   char c{'\0'}; //Should be at end, if not, the string contained more than just a number   i >> c;   if (i) return false;   return true; } #include <boost/lexical_cast.hpp> ///IsInt determines if std::string can be converted to integer. ///From http://www.richelbilderbeek.nl/CppIsInt.htm bool IsIntBoost(const std::string& s) noexcept {   try   {     boost::lexical_cast<int>(s);     return true;   }   catch (boost::bad_lexical_cast&)   {     return false;   } } #include <cassert> int main() {   assert(IsIntStl("3"));   assert(IsIntStl("0"));   assert(IsIntStl("-23"));   assert(!IsIntStl("a"));   assert(!IsIntStl("2+fire"));   assert(IsIntBoost("3"));   assert(IsIntBoost("0"));   assert(IsIntBoost("-23"));   assert(!IsIntBoost("a"));   assert(!IsIntBoost("2+fire")); }