[Bug libstdc++/93584] std::string::find_first_not_of is about 9X slower than strspn

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93584

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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           Keywords|                            |missed-optimization

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Guess the implementation is a bit naiive, testing a single char at a time
when glibc likely contains more optimized variants.  Not sure if constraints
would allow calling strspn from libstdc++ ...