[Issue 13348] std.uni.byGrapheme is impure

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13348

Thayne <astrothayne at gmail.com> changed:

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                 CC|                            |astrothayne at gmail.com

--- Comment #3 from Thayne <astrothayne at gmail.com> ---
I don't think byGrapheme can be pure in general, because, in general, the input
range used doesn't necessarily have pure input methods. For example the input
range could read from I/O.

The solution would probably be to add pure if and only if the front, popFront,
and empty methods of the inputRange are themselves pure.

I'm not sure what the best way to do that would be.

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