CA2265: Do not compare Span<T> to null or default
| Property | Value |
|---|---|
| Rule ID | CA2264 |
| Title | Do not compare Span<T> to null or default |
| Category | Usage |
| Fix is breaking or non-breaking | Non-breaking |
| Enabled by default in .NET 9 | As warning |
Cause
A Span<T> instance is compared to null or default.
Rule description
Comparing a span to null or default might not do what you intended. default and the null literal are implicitly converted to Span<T>.Empty.
How to fix violations
Remove the redundant comparison or make the code more explicit by calling IsEmpty instead.
Example
The following code snippet shows two violations of CA2265 and the fix for the violations.
Span<int> span = new([1, 2, 3]);
// CA2265 violation.
if (span == null) { }
// CA2265 violation.
if (span == default) { }
// Fixes the violation.
if (span.IsEmpty) { }
When to suppress warnings
It's safe to suppress this warning if you meant to compare the span to the empty span.
Suppress a warning
If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.
#pragma warning disable CA2265
// The code that's violating the rule is on this line.
#pragma warning restore CA2265
To disable the rule for a file, folder, or project, set its severity to none in the configuration file.
[*.{cs,vb}]
dotnet_diagnostic.CA2265.severity = none
For more information, see How to suppress code analysis warnings.
