Question

I have the following vector passed to a function

void WuManber::Initialize( const vector<const char *> &patterns, 
                      bool bCaseSensitive, bool bIncludeSpecialCharacters, bool bIncludeExtendedAscii )

I want to erase any element that is less in length than 2
I tried the following but it didn’t compile even
can you tell me what I am missing here.

for(vector<const char *>::iterator iter = patterns.begin();iter != patterns.end();iter++)
 {//my for start
 size_t lenPattern = strlen((iter).c_str);
 if ( 2 > lenPattern )
 patterns.erase(iter);
 }//my for end

Answer 1

This cannot work, because if you erase something from your vector you invalidate your iterator.

It probably does not compile because you use your iterater in a wrong way. You might try iter->c_str or (*iter).c_str. On the other hand, give us the error message 😉

Next thing, you try to modify a const vector. This is why the compiler is complaining.

You could do this with an index, like this:

for (int i = 0; i < patterns.size(); ++i) {
    size_t lenPattern = strlen(patterns[i]);
    if (2 > lenPattern) {
      patterns.erase(patterns.begin() + i);
      --i;
    }
}

However, this is not very elegant, as I manipulate the counter…