TFA links to what arenas are and where they come from, how some bits included here would not really be part of this library but assumed part of the project using these techniques, does explain the general point of the exercise, and how this isn't even strictly a suggestion for a library but a "potpouri of techniques".
They are fully aware of -lre and assume that everyone else is too. This isn't about just achieving regex somehow. It's about avoiding the crt and gc and c++ in general while using an environment that normally includes all that by default.
You don't redefine new just to get regex. Obviously there must be some larger point and this regex is just some zoomed-in detail example of existing and operating within that larger point.
They are fully aware of -lre and assume that everyone else is too. This isn't about just achieving regex somehow. It's about avoiding the crt and gc and c++ in general while using an environment that normally includes all that by default.
You don't redefine new just to get regex. Obviously there must be some larger point and this regex is just some zoomed-in detail example of existing and operating within that larger point.