Boost.Lexical_Cast in C++
Boost.LexicalCast which is defined in the Library “boost/lexical_cast.hpp” provides a cast operator, boost::lexical_cast, that can convert numbers from strings to numeric types like int or double and vice versa. boost::lexical_cast is an alternative to functions like std::stoi(), std::stod(), and std::to_string(), which were added to the standard library in C++11. Now let see the Implementation of this function in a program. Examples:
Conversion integer -> string string- > integer integer -> char float- > string
Associated exceptions : If a conversion fails, an exception of type bad_lexical_cast, which is derived from bad_cast, is thrown. It throws an exception because the float 52.50 and the string “w3wiki” cannot be converted to a number of type int.
CPP
// CPP program to illustrate // Boost.Lexical_Cast in C++ #include "boost/lexical_cast.hpp" #include <bits/stdc++.h> using namespace std; using boost::lexical_cast; using boost::bad_lexical_cast; int main() { // integer to string conversion int s = 23; string s1 = lexical_cast<string>(s); cout << s1 << endl; // integer to char conversion array< char , 64> msg = lexical_cast<array< char , 64>>(45); cout << msg[0] << msg[1] << endl; // string to integer conversion in integer value int num = lexical_cast< int >("1234"); cout << num << endl; // bad conversion float to int // using try and catch we display the error try { int num2 = lexical_cast< int >("52.20"); } // To catch exception catch (bad_lexical_cast &e) { cout << "Exception caught : " << e.what() << endl; } // bad conversion string to integer character // using try and catch we display the error try { int i = lexical_cast< int >("w3wiki"); } // catching Exception catch (bad_lexical_cast &e) { cout << "Exception caught :" << e.what() << endl; } return 0; } |
Output:-
23 45 1234 Exception caught : bad lexical cast: source type value could not be interpreted as target Exception caught :bad lexical cast: source type value could not be interpreted as target
Reference :- http://www.boost.org/