Incorrect IDE0004: Remove unnecessary cast

I am currently unsure if its really a roslyn bug or a c# bug or both.

Version Used:

Microsoft Visual Studio Enterprise 2022
Version 17.0.0
VisualStudio.17.Release/17.0.0+31903.59
Microsoft .NET Framework
Version 4.8.04084

dotnet 6 / C# 10

Steps to Reproduce:

Code:

var (isEdge, moreOnes) = (true, false);

char? expected_a = isEdge ? null : moreOnes ? '1' : '0';
char? expected_b = isEdge ? null : moreOnes ? '0' : '1';

(char? expected_a_01, char? expected_b_01) = isEdge ? default : moreOnes ? ((char?)'1', (char?)'0') : ('0', '1');
(char? expected_a_02, char? expected_b_02) = isEdge ? default : moreOnes ? ('1', '0') : ('0', '1');

Debug.Assert(expected_a == expected_a_01 && expected_a == expected_a_02);
Debug.Assert(expected_b == expected_b_01 && expected_b == expected_b_02);

Expected Behavior: expected_a, expected_a_01 and expected_a_02 should be equal. (Namely, null) The analyzer tells me, that both casts are redundant.

Actual Behavior: expected_a_02 and expected_b_02 both have the value 0

[CyrusNajmabadi]

@JKamsker Correct. As i mentioned, this is fixed in 17.1 (not 17.0) and i have a PR out showing that this no longer reproes to ensure this doesn’t regress. Thanks!

[CyrusNajmabadi]

Not a problem at all. Nothing to be sorry about. 😃