* $S> ( $: a$ -- S: a.str )

Drop a$ from the string stack and leave it as a Forth string
a.str, without copying. "string-s-from"
WARNING:  If a$ is a bound string, it may move or disappear

at the next garbage collection, making a.str invalid. This
can be avoided by sandwiching sections of code where this
could occur between $GC-OFF and $GC-ON.

FORTH/DEF dstrings ordinary primitive