Fix: specified type is not checked for use! binding

[edgarfgp]

Description

Fixes #19005

Checklist

• Test cases added
• Release notes entry updated

[github-actions]

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@edgarfgp,

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[auduchinok]

The naive approach of simply copying the type node doesn't look correct to me, because of how types of the bound expressions and the patterns rarely match.

Please let's not merge it until a proper explanation is provided.

[auduchinok]

@edgarfgp Could you explain this logic in greater detail, please?

There're very tricky details related to the types in computation expression builder methods, so I think it would be nice if everyone could follow your thought process here.

[DedSec256]

It also seems to follow that such code will compile, even though it is erroneous.

open System

async {
    use! (x: string): IDisposable = async { return null }
    return x
}

[edgarfgp]

@auduchinok My current attempt is to move the annotation off the Bind lambda parameter to the value we pass to Using so we don't force Bind type parameter(We let Bind pick the right input type from overloads by leaving the lambda parameter untyped.), but we still type-check the user’s annotation and report errors. But as Alex shared this wont be enough. My goal here is to find the minimal fix for this issue. Not to redesign the ExprAsUseBang case.