Diacritical marks in regular expression causes unexpected behavior - c++

Question

I check name validity by this regular expression, allowing any symbol as suggested here:
// Allow any symbol
const QString validNameMatcher = QStringLiteral("^[a-zA-Z0-9 _.,!()+=`,\"#$#%*-]+$");
bool Class::isNameValid(const QString fileName)
{
QRegularExpression re(validNameMatcher);
QRegularExpressionMatch match = re.match(fileName);
if (match.hasMatch())
return true;
else
return false;
}
For a file name like 1111 Rick (wow) L50-57.stl the above function returns true. So far so good.
To allow diacritical marks, I just add [À-ž] to the name-matcher as suggested here:
// [À-ž] is for diacritical marks
const QString validNameMatcher = QStringLiteral("^[a-zA-Z0-9À-ž _.,!()+=`,\"#$#%*-]+$");
After adding [À-ž], surprisingly, for the same file name of 1111 Rick (wow) L50-57.stl, the above function returns false. Am I missing something?
UPDATE
As suggested by #WiktorStribiżew , I used UseUnicodePropertiesOption:
QRegularExpression re(validNameMatcher, QRegularExpression::PatternOption::UseUnicodePropertiesOption);
But it didn't work. The result is the same as before.
Also (*UTF) doesn't work:
const QString validNameMatcher = QStringLiteral("(*UTF)^[a-zA-Z0-9À-ž _.,!()+=`,\"#$#%*-]+$");

Answer 1

The key point is #WiktorStribiżew solution of using QRegularExpression::UseUnicodePropertiesOption option:
QRegularExpression re(validNameMatcher, QRegularExpression::PatternOption::UseUnicodePropertiesOption);
But as mentioned on its documentation:
QRegularExpression::UseUnicodePropertiesOption
The meaning of the \w, \d, etc., character classes, as well as the meaning of their counterparts (\W, \D, etc.), is changed from matching ASCII characters only to matching any character with the corresponding Unicode property.
So, it occurred to me to replace [a-zA-Z0-9À-ž_] in my regular expression with just [\w]:
// Bad:
const QString validNameMatcher = QStringLiteral("^[a-zA-Z0-9À-ž _.,!()+=`,\"#$#%*-]+$");
// Good:
const QString validNameMatcher = QStringLiteral("^[\\w .,!()+=`,\"#$#%*-]+$");
Now, isNameValid() function returns expected results.