An out parameter cannot have the '[in]' attribute
Currently, the in attribute is not permitted on an out parameter.
The following sample generates CS0036:
using System; public class MyClass { public static void TestOut([in] out char TestChar) { // CS0036 // try the following line instead // public static void TestOut(out char TestChar) { TestChar = 'b'; Console.WriteLine(i); } public static void Main() { char i; // variable need not be initialized TestOut(out i); // the arg must be passed as out Console.WriteLine(i); } }