Replace capture group while preserving surrounding capture

[tqwewe]

Describe your feature request

I am unable to replace an nth's capture group when using Regex::replace/Regex::replace_all.

For example, I have the following regex: class(?:Name)?=["'](.*)["'] which matches class="container" and className='container'.

I need to replace only the container while preserving the surrounding text in the capture.

ex.replace_all(&content, |caps: &Captures| {
  let classes = caps.get(1).unwrap().as_str().to_owned() + " new-class";
  
  // What do I return here to keep the `class="` and `"` while replacing the content between?
})