Bug 12184 - Expression can be reduced to delegate fix can create ambiguity
Summary: Expression can be reduced to delegate fix can create ambiguity
Status: RESOLVED FIXED
Alias: None
Product: Xamarin Studio
Classification: Desktop
Component: C# Binding ()
Version: 4.0.4
Hardware: PC Mac OS
: Normal normal
Target Milestone: 4.0.9 (from master)
Assignee: Mike Krüger
URL:
Depends on:
Blocks:
 
Reported: 2013-05-09 14:42 UTC by Mikayla Hutchinson [MSFT]
Modified: 2013-06-24 16:18 UTC (History)
1 user (show)

Tags:
Is this bug a regression?: ---
Last known good build:

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Status:
RESOLVED FIXED

Description Mikayla Hutchinson [MSFT] 2013-05-09 14:42:31 UTC
Applying the fix from the "Expression can be reduced to delegate" inspection on the following code creates an overload resolution ambiguity.

public static void Foo ()
{
	var wr = WebRequest.Create ("http://xamarin.com");
	Task.Factory.StartNew (() => wr.GetResponse ());
}

Gets "fixed" to

public static void Foo ()
{
	var wr = WebRequest.Create ("http://xamarin.com");
	Task.Factory.StartNew (wr.GetResponse);
}

Which fails to compile because apparently it's ambiguous between StartNew(Action) and StartNew<WebResponse>(Func<WebResponse>)

It can be fixed by a cast:

public static void Foo ()
{
	var wr = WebRequest.Create ("http://xamarin.com");
	Task.Factory.StartNew ((Func<WebResponse>)wr.GetResponse);
}
Comment 1 Mike Krüger 2013-05-10 05:59:59 UTC
fixed
Comment 2 PJ 2013-06-24 16:18:47 UTC
This bug was marked as fixed for Xamarin Studio 4.0.9, which is currently in the beta channel. Try it out!