Yes, it is acceptable syntax to do this.
In fact, I always do this in my implementations, because it then is trivial to copy and paste a method definition from interface to implementation and vice versa without having to remember where you are. It helps that I use aligned brackets on separate lines, as well.
Wil Shipley agrees with me on this:
End the definition lines on your
method implementations with a
semicolon, so you can copy-n-paste
them to or from your header (or the
“Private” category at the top of your
file) as needed when they change.
Semicolons are required in the
“interface” section, but don’t hurt
anything in the “implementation”
section.