I am using PhpStorm 10.0 but the new php 7.1 syntax is not correctly parsed.
For instance, the following getter is considered invalid syntax:
public function notes(): ?string
{
return $this->notes;
}
Is it possible to make PhpStorm 10.0 php 7.1-aware or do I need to upgrade to the new version?
Is it possible to make PhpStorm 10.0 php 7.1-aware
No.
or do I need to upgrade to the new version?
Yes.
You need at very least 2016.2.2 for such syntax to be supported (latest at the moment is 2017.2.1).