Cause

When a value that's known to never be null is passed toArgumentNullException.ThrowIfNull(), an exception is never thrown, making the statement a no-op.

Rule description

ArgumentNullException.ThrowIfNull throws when the passed argument isnull. Certain constructs like non-nullable structs (except forNullable<T>), type parameters known to be non-nullable structs, 'nameof()' expressions, and 'new' expressions are known to never be null, soArgumentNullException.ThrowIfNull will never throw.

In the case of a struct, sinceArgumentNullException.ThrowIfNull accepts anobject?, the struct is boxed, which causes an additional performance penalty.

How to fix violations

Remove theArgumentNullException.ThrowIfNull call.

Example

The following code snippet shows a violation of CA2264:

static void Print(int value){    ArgumentNullException.ThrowIfNull(value);    Console.WriteLine(value);}

The following code snippet fixes the violation:

static void Print(int value){    Console.WriteLine(value.Value);}

When to suppress warnings

It's always safe to suppress this warning.

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 CA2264// The code that's violating the rule is on this line.#pragma warning restore CA2264

To disable the rule for a file, folder, or project, set its severity tonone in theconfiguration file.

[*.{cs,vb}]dotnet_diagnostic.CA2264.severity = none

For more information, seeHow to suppress code analysis warnings.