CA1871.md

Pattern: Use of nullable struct for ArgumentNullException.ThrowIfNull

Issue: -

Description

When a nullable struct, for example, int? or Guid?, is passed to ArgumentNullException.ThrowIfNull, it's boxed to an object, causing a performance penalty.

Example of incorrect code:

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

Example of correct code:

static void Print(int? value)
{
    if (!value.HasValue)
    {
        throw new ArgumentNullException(nameof(value));
    }

    Console.WriteLine(value.Value);
}

Further Reading

• CA1871