Remove some unnecessary Substrings

[stephentoub]

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Issue Details

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Author:	stephentoub
Assignees:	stephentoub
Labels:	area-Meta
Milestone:	-

[ShreyasJejurkar]

I thought the AsSpan analyzer works on substrings as well, but looks like its only works when used as Range based operator! :(
https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca1831

Can't we extend this analyzer to highlight the SubString usage as well!? Thoughts?

[stephentoub]

Can't we extend this analyzer to highlight the SubString usage as well!? Thoughts?

Most of these would be challenging to catch in an analyzer in any time-boxed manner, e.g. where you're calling a method that accepts and returns a string, where the output of that method is fed into one that can take either a substring or a span, where the input to the method is being substring'd, and, critically, where the analyzer can see into the implementation of that called method and determine that both its argument and return value could be changed to spans without changing semantics.