rspec/rules/S4061/csharp/rule.adoc

== Why is this an issue?

A method using the ``++VarArgs++`` calling convention is not Common Language Specification (CLS) compliant and might not be accessible across programming languages, while the ``++params++`` keyword works the same way and is CLS compliant.


This rule raises an issue when a ``++public++`` or ``++protected++`` type contains a ``++public++`` or ``++protected++`` method that uses the ``++VarArgs++`` calling convention.


=== Noncompliant code example

[source,csharp]
----
using System;

namespace MyLibrary
{
    public class Foo 
    {
        public void Bar(__arglist) // Noncompliant
        { 
            ArgIterator argumentIterator = new ArgIterator(__arglist);
            for(int i = 0; i < argumentIterator.GetRemainingCount(); i++) 
            { 
                Console.WriteLine(
                    __refvalue(argumentIterator.GetNextArg(), string));
            } 
        }
    }
}
----


=== Compliant solution

[source,csharp]
----
using System;

[assembly: CLSCompliant(true)]
namespace MyLibrary
{
    public class Foo 
    {
        public void Bar(params string[] wordList)
        { 
            for(int i = 0; i < wordList.Length; i++) 
            { 
                Console.WriteLine(wordList[i]);
            } 
        }
    }
}
----


=== Exceptions

Interop methods using ``++VarArgs++`` calling convention do not raise an issue.

[source,csharp]
----
[DllImport("msvcrt40.dll")]
public static extern int printf(string format, __arglist); // Compliant
----

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Use the "params" keyword instead of "__arglist".


=== Highlighting

Method declaration


endif::env-github,rspecator-view[]