A surprising fact I just learned about float parsing is that it is absolutely trivial (and, I expect, very fast) if you are willing to tolerate a 1 ULP inaccuracy: https://www.exploringbinary.com/quick-and-dirty-decimal-to-f...

(Though 1/100M randomly tested conversions had a 14ULP inaccuracy, so I guess the inaccuracy is a bit unpredictable).