Feature #18597
Updated by danh337 (Dan H) about 2 years ago
This is related to #16295, but focuses only on the `.+@` part.
Currently we can use `.dup` in a method chain when we need to mutate a String.
However there are cases where the code's context *expects* the String to be mutated. In cases like this, `.dup` always works, but we don't want to duplicate a String that is already mutable.
Since `.+@` looks more like an operator, it can be unintuitive in a method chain, so this is asking for a new named method that can be used in its place, instead of always `.dup`.
For example:
```
def add_result_text(buffer, new_result)
text = "#{new_result.count} #{new_result.input} #{do_fancy_calc(new_result)}\n"
buffer.dup_if_immutable << text
# ^^^^^^^^^^^^^^^^ new method?
end
buffer = "" # ...maybe immutable
get_lots_of_results.each do |result|
add_result_text(buffer, result)
end
```