Unmanaged constraint allows only non-nullable types #15876
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BillWagner
approved these changes
Nov 18, 2019
now.
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The
unmanagedconstraint implies thestructconstraint and, thus, doesn't allow nullable value types. Beginning with C# 8.0, for an unmanaged value typeT, the nullable typeT?is also unmanaged but doesn't satisfy theunmanagedconstraint because of the underlyingstructconstraint. This is how it's now, but may be changed in future. For more information, see dotnet/csharplang#2916