Абмеркаванне

@aras fast_float

@vitaut so... which one they forgot to include?

@aras from_chars although on further inspection the latter is just a wrapper around strtod on libstdc++

@aras I guess on the parsing side the sitation is not as bad, something like 6x perf difference between fast_float and stdtod, not 50-100x like on the formatting side.