[Issue 11229] std.string.toLower is slow

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=11229

--- Comment #6 from Jack Stouffer <jack at jackstouffer.com> ---
This,

(cast(string)"pg1342.txt".read).map!toLower.array

is almost three times faster than 

(cast(string)"pg1342.txt".read).toLower

because of the ASCII optimizations in dchar toLower(dchar c)

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