Is it possible do not copy ref to local variable?

Question

I'm trying declare ref object as optional parameter. So I've understood why I can't do that. The decesion was to overload my method and now I have a new problem:

public Guid GetIdByEmployeeTypeName(string typeName)
{
    return SurroundWithTryCatch(() => new EmployeeType().GetEmployerGroupIdByTypeName(typeName));
}

public Guid GetIdByEmployeeTypeName(string typeName, ref EmployeeType employeeType)
{
    EmployeeType type = employeeType; //The problem here. I can not use ref object inside an anonymous method.
    return SurroundWithTryCatch(() => type.GetEmployerGroupIdByTypeName(typeName));
}

How can I optimize my code?

Can I ask a semi-related question, why do you need to pass `EmployeeType` by ref, is it a struct? — CodingGorilla, Mar 23 '16 at 16:39
You don't assign anything to `employeeType` whatsoever. Why do you even need `ref` modifier here? — Sriram Sakthivel, Mar 23 '16 at 16:48
@SriramSakthivel Not to copy the object. As I know ref in C# the same thing with & in C++.. — user3818229, Mar 23 '16 at 16:52
@HenkHolterman As I know wothout `ref` it copy object to stack. Am I wrong? — user3818229, Mar 23 '16 at 16:56
@user3818229 No it's not the same - `ref` indicates a parameter is passed _by reference_ in C#. Unless you are going to change which object `employeeType` references, you do not need `ref`. It's also unclear what you expest the assignment to `type` to do. Do you intend it to "clone" `employeeType`? — D Stanley, Mar 23 '16 at 16:57
@user3818229 It will not copy the object unless `EmployeeType` is a `struct`. — D Stanley, Mar 23 '16 at 16:57
@user3818229 I would suggest you read up on `ref` and the difference between value types and reference types. Don't assume that the concepts and constructs in a managed language like C# are the same as an unmanaged one like C++. — D Stanley, Mar 23 '16 at 16:59
@DStanley Is there only a one way when I need to use `ref` with struct? — user3818229, Mar 23 '16 at 16:59
@user3818229 Only when using interop, or you want to mutate the struct, but mutable structs can cause all sorts of problems, so they are usually avoided at all costs. — D Stanley, Mar 23 '16 at 17:02
If you aren't sure, don't use `ref` or `struct`. I don't see why you need them here. — Jodrell, Mar 23 '16 at 17:02
Regarding [`ref`](http://stackoverflow.com/a/635934/1997232). — Sinatr, Mar 23 '16 at 17:03
@user3818229 I ceratinly wouldn't do it to avoid "copying to the stack". Don't try to fix memory problems until you are certain there _is_ a problem. — D Stanley, Mar 23 '16 at 17:03
@DStanley I read information about `ref` and `out`. Everything clear in my mind right now! Thanks everyone! — user3818229, Mar 23 '16 at 17:08

score 0 · Accepted Answer · answered Mar 23 '16 at 16:54

I wouldn't say it's a good (or very bad) idea, but you can create overload without ref and call method requiring one with value which is not used to return:

public Guid GetIdByEmployeeTypeName(string typeName)
{
    var tmp = new EmployeeType();
    return GetIdByEmployeeType(typeName, ref tmp);
}

Is it possible do not copy ref to local variable?

1 Answers1