Skip to content

Nullness issue - ToString on an integer with UoM takes nullness information from ValueType #17539

Description

@kerams

Issue description

image

Similarly with UMX when the underlying type is a reference type, nullness is inherited from Object.ToString, rather than the underlying type, whose overriden ToString is not null.

Choose one or more from the following categories of impact

  • Unexpected nullness warning (false positive in nullness checking, code uses --checknulls and langversion:preview).
  • Missing nullness warning in a case which can produce nulls (false negative, code uses --checknulls and langversion:preview).
  • Breaking change related to older null constructs in code not using the checknulls switch.
  • Breaking change related to generic code and explicit type constraints (null, not null).
  • Type inference issue (i.e. code worked without type annotations before, and applying the --checknulls enforces type annotations).
  • C#/F# interop issue related to nullness metadata.
  • Other (none of the categories above apply).

Operating System

Windows (Default)

What .NET runtime/SDK kind are you seeing the issue on

.NET SDK (.NET Core, .NET 5+)

.NET Runtime/SDK version

9.0.0-preview.7.24405.7

Reproducible code snippet and actual behavior

>(1).ToString();;valit:string = "1"
>[<Measure>]typeid;;[<Measure>]typeid>1<id>.ToString ();;valit:string | null= "1"

Possible workarounds

Unchecked.nonNull

Metadata

Metadata

Assignees

No one assigned

    Labels

    Area-NullnessIssues related to handling of Nullable Reference TypesBugImpact-Low(Internal MS Team use only) Describes an issue with limited impact on existing code.help wanted

    Type

    Projects

    Status
    New

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions