Re: [icu-design] ICU API proposal: Replace const StringPiece& with StringPiece

[Yoshito U. <yos...@us...>]

> With modern compilers, trivially copyable user-defined types are 
> simpler and more efficient to pass by value than by reference. Ticket 
#12140
> therefore suggests replacing const StringPiece& in the ICU code base
> with passing StringPiece by value.

This proposal will introduce a change in existing API, although many use 
cases are not affected.
I think you should show actual numbers indicating performance improvement 
with this change.

-Yoshtio