WRT interpolation in /$pat/g: Actually it is fast. When the entire pattern consists of an interpolated qr reference, no recompilation takes place at runtime, so the speed gain of precompilation is not lost. You can observe this with a combination of perl -Dts and reading the source code of pp_regcomp.

WRT the missing //g: It's a fair cop, but society's to blame. :-)

    -- Chip Salzenberg, Free-Floating Agent of Chaos