Passing an object from F# into a C# method which takes it as an out parameter doesn't work?

c#, f#, pass-by-reference

Solution

Try

// let parameterSet = null;
let retval, parameterSet = currentPanel.GetParamterSet(name);

You shouldn't pass an instance as `ref` parameter, when the method expects an out parameter (which upon calling should be an unassigned reference preceded by the `out` keyword).

Problem

One of the libraries I'm using defines this in C#: ``` public ushort GetParameterSet(string name, out ParameterSet parameterSet) ``` I'm trying to call this from F#: ``` let parameterSet = new ParameterSet(); let retVal = currentPanel.GetParameterSet(name, ref parameterSet); ``` However, even though the parameterSet is set to an instance of that class with valid data in the C# method, it does not change in F#. What am I missing here?

Original source