Small-size-optimized Appender

[Per Nordlöw]

On Friday, 16 October 2020 at 20:55:07 UTC, Paul Backus wrote:
> Immediately-called lambdas are always inlined, even by DMD in 
> non-release mode.

Nice. Thanks. I still believe

     @trusted { ... }

would be more appreciated, though. I always forget the syntax for 
inline lambdas and I've been using D since 2013.

Has there been any objections against adding something similar?