std::string related errors and handling them, c++

Question

Alright, it might be a stupid question, but I will go ahead and ask anyway.

So, I was wondering, what are all the possible errors associated with std::string usage ? I know a few, for example accessing char at location greater then the std::string size in various std::string functions.

While programming what errors should I keep in mind and place checks on ?

And is there an another way to do following for example, efficiently ?

std::string s("some string.");

int i = s.find ( "." );


if (  i != std::string::npos    &&  i + 3 < s.length (  )  ) // <<== this check is what I am talking about
    s.erase ( i + 3 );

I have a program, which requires hundreds of such checks, so I was wondering, there was an another way then to do if( some_condition ) each time.

put it in a function.

Luchian Grigore
– Luchian Grigore

2013-08-12 07:54:05 +00:00
Commented Aug 12, 2013 at 7:54 — Luchian Grigore
– Luchian Grigore, Commented Aug 12, 2013 at 7:54
@LuchianGrigore that seems a better option.

StudentX
– StudentX

2013-08-12 09:31:21 +00:00
Commented Aug 12, 2013 at 9:31 — StudentX
– StudentX, Commented Aug 12, 2013 at 9:31
@StudentX: So, did you get your answer?

Lightness Races in Orbit
– Lightness Races in Orbit

2013-08-14 10:08:56 +00:00
Commented Aug 14, 2013 at 10:08 — Lightness Races in Orbit
– Lightness Races in Orbit, Commented Aug 14, 2013 at 10:08

Lightness Races in Orbit · Accepted Answer · 2013-08-12 07:59:38Z

2

You don't need to list every error case for the whole class; just look up the documentation for the functions that you use, which typically lists preconditions.

For example, cppreference.com's page on std::string::erase.

answered Aug 12, 2013 at 7:59

Lightness Races in Orbit

387k77 gold badges672 silver badges1.1k bronze badges

Sign up to request clarification or add additional context in comments.

Comments

P0W · Accepted Answer · 2013-08-12 09:16:27Z

0

If i greater than the string length, an out_of_range exception is thrown

Ref:- std::string::erase

So you can always catch it !

std::string s("some string.");
int i = s.find ( "." );

if (i != std::string::npos)
try 
{
   s.erase ( i + 3 );
}
catch (const std::out_of_range& err) 
{
  std::cerr << "Out of Range error: " << err.what() << std::endl;
}

edited Aug 12, 2013 at 9:16

answered Aug 12, 2013 at 8:06

P0W

48.1k9 gold badges79 silver badges124 bronze badges

3 Comments

Hulk Over a year ago

But then, in this case, this approach might not be advisable if input strings with '.'s in arbitrary are perfectly legal and to be expected. If this situation indicates corrupted data or something like that, I agree that throwing the exception and handling it can indeed be the better way.

StudentX Over a year ago

unfortunately that's doesn't make life easy :(

P0W Over a year ago

@StudentX well then in that case I'd suggest writing your own erase and which put boundary checking on the pos

Collectives™ on Stack Overflow

std::string related errors and handling them, c++

2 Answers 2

Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related