catch is a keyword to mark a catch-block. A catch-block is always preceded by a try-block in which an exception might be thrown. The exception can be caught by the subsequent catch-block.

The code below shows the function CanLexicalCast, which returns true if a certain std::string can be converted to another data type (an int, for example). The risky operation, the conversion, is put in the try-block.


#include <cassert>

#include <string>

#include <boost/lexical_cast.hpp>

 

//From http://www.richelbilderbeek.nl/CppCanLexicalCast.htm

template <class TargetType>

bool CanLexicalCast(const std::string& from)

{

  try

  {

    boost::lexical_cast<TargetType>(from);

  }

  catch (boost::bad_lexical_cast)

  {

    return false;

  }

  catch (...)

  {

    assert(!"Something unexpected happened");

    throw;

  }

  return true;

}

Advice

Don't try to catch every exception in every function [1]
Always catch exception& and ... [3]
Have main catch and report every exception [2]

Reference

Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 13.7. Advice. page 387: '[8] 'Don't try to catch every exception in every function'
Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 13.7. Advice. page 387: '[27] 'Have main() catch and report every exception'
Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 30.5. Advice. page 883: '[10] Always catch exception& (for standard-library and language support exceptions) and ... (for unexpected exceptions)'

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(C++) catch

Advice

Reference