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std::basic_ios<CharT,Traits>::exceptions

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< cpp‎ | io‎ | basic ios
 
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std::basic_ios
 
std::ios_base::iostate exceptions() const;
 (1)
void exceptions( std::ios_base::iostate except );
 (2)

Gets and sets the exception mask of the stream. The exception mask determines which error states trigger exceptions of type failure.

1) Returns the exception mask.
2) Sets the exception mask to except.

Contents

[edit] Parameters

except - exception mask

[edit] Return value

1) The current exception mask.
2) (none)

[edit] Notes

This section is incomplete
Reason: discuss LWG2349 and link from ios_base::clear, and from (un)formatted(i/o)utputfunction requirement pages (or perhaps the behavior should be fully elaborated on the requirement pages and linked from here). See also stackoverflow.com/a/35089910

[edit] Example

Run this code
#include <iostream>
#include <fstream>
 
int main() 
{
    int ivalue;
    try {
        std::ifstream in("in.txt");
        in.exceptions(std::ifstream::failbit); // may throw
        in >> ivalue; // may throw
    } catch (const std::ios_base::failure& fail) {
        // handle exception here
        std::cout << fail.what() << '\n';
    }
}

Possible output: 

basic_ios::clear: iostream error
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