removing elements from QStringList

[user4592357]

i have a similar code:

QStringList lst;
// fill lst with values

std::vector<bool> valid(lst.size(), true);
// set values to false if necessary

// now, remove invalid elements
int i = 0;
for (auto val : lst)
{
	if (!valid[i])
		lst.removeOne(val);
	++i;
}

this is what i have now but i really don't like having the loop and doing this. what else can i do? i don't care if it's a Qt solution or STL algorithm or whatever.

[Alvaro Denis]

Try this:

int main(int argc, char *argv[]) {
  QStringList lst{"dfdfdfdf", "89", "d89fd8f&*", "dfdf", "ds"};
  lst.erase(std::remove_if(lst.begin(), lst.end(),
                 [](const QString &s) { return s.size() > 5; }), lst.end());
  qDebug() << lst;
}

Use your "valid" logic into the lambda.

[SGaist]

Hi,

To add to @Alvaro-Denis, you should make s a const reference to avoid needless copies.

[user4592357]

@SGaist
i know. i always do that. thanks

[Alvaro Denis]

@user4592357 I was improve the code in my original response based on the @SGaist suggestion, but in general be careful with the "i always", specifically on lambda, consider this

[user4592357]

@Alvaro-Denis
which part should have i be careful about? it says nothing about parameters, only captures.