Re: iterator==0? (std::list::iterator)
Dani wrote:
"Ulrich Eckhardt" <eckhardt@satorlaser.com> wrote in message
news:plvap4-gpm.ln1@satorlaser.homedns.org...
Dani wrote:
If I set and iterator to 0
This doesn't work, and if it works the results are not guaranteed by the
C++
standard. This topic came up right here with the subject "assigning NULL
to
an iterator", please read the archives.
Uli
>
> The thing is i'm using std::list so I can't just use an index
> ([]operator) and use -1 for invalid, So I guess I'm gonna define
> a bool variable to determine if the iterator is
> valid.
See examples for usage of std::find, which returns the end iterator:
....
std::list<int> ints;
....
if( ints.end() == std::find( ints.begin(), ints.end(), 123 ) )
{
// 123 not found
}
You need to educate yourself on the concepts behind iterators,
containers and ranges. These are built upon the concept of a half-open
range. That is, the end iterator is one past the end of the iterable
items. This indicates what you refer to above as an 'invalid' item position.
Jeff
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