Re: exception error

From:

Thiago Adams <thiago_adams@hotmail.com>

Newsgroups:

comp.lang.c++.moderated

Date:

Thu, 25 Oct 2007 18:23:18 CST

Message-ID:

<1193330521.453117.58310@v23g2000prn.googlegroups.com>

On 25 Oct, 11:25, mattia.lipr...@gmail.com wrote:

Hello, i've this problem:
I'd like to catch this exception, for example see this code

#include "stdexcept"
float f;
try{
        cout << "Insert value:" << endl;
        cin >> f;
        }catch( runtime_error err){
                cout << err.what();

}

what's happen if the user will insert a string instead of a float?
What i've to do if i want to catch this exception?

Hi,

See the documentation of ios_base::exceptions().

Example:

class UseExceptionsHere
{
     std::ios_base::iostate previous_state;
     std::ios_base & m_io;

     UseExceptionsHere & operator =(const UseExceptionsHere &);//

public:
     UseExceptionsHere(std::ios_base & io) : m_io(io) {
         previous_state = m_io.exceptions();
         m_io.exceptions(ios_base::badbit | ios_base::failbit);
     }

     ~UseExceptionsHere() { m_io.exceptions(previous_state); }
};

    float f;
     try{
         UseExceptionsHere useExceptionsHere(cin);
         cout << "Insert value:" << endl;
         cin >> f;

     }catch( runtime_error err) {
         cout << err.what();
     }

-----
Thiago Adams
http://paginas.terra.com.br/informatica/thiago_adams/

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