(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)

Qt Creator 3.1.1

Console application

C++98

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")); }