C# 10: Validating Arguments with CallerArgumentExpression

Writing guard clauses like `ArgumentNullException.ThrowIfNull(value)` is great, but error messages often lack context. CallerArgumentExpression captures the expression text at compile time.

Example

public static void Validate(
    bool condition,
    [CallerArgumentExpression("condition")] string? expression = null)
{
    if (!condition)
        throw new ArgumentException($"Failed: {expression}");
}

// Usage
Validate(user.Age >= 18);
// Exception message: "Failed: user.Age >= 18"

Key Takeaways

• Zero runtime overhead—it’s a compile-time feature.
• Use in custom assertion libraries or fluent validation.