ref

I'm navigating the ins and outs of ref returns, and am having trouble emitting a dynamic method which returns by ref. Handcrafted lambdas and existing methods work as expected: class Widget { public int Length; } delegate ref int WidgetMeasurer(Widget w); WidgetMeasurer GetMeasurerA() { return w => ref w.Length; } static ref int MeasureWidget(Widget w) => ref w.Length; WidgetMeasurer GetMeasurerB() { return MeasureWidget; } But emitting a dynamic method fails. Note : I'm using Sigil here. Apologies, I'm less familiar with System.Reflection.Emit . WidgetMeasurer GetMeasurerC() { FieldInfo

I have inherited some code that uses the ref keyword extensively and unnecessarily. The original developer apparently feared objects would be cloned like primitive types if ref was not used, and did not bother to research the issue before writing 50k+ lines of code. This, combined with other bad coding practices, has created some situations that are absurdly dangerous on the surface. For example: Customer person = NextInLine(); //person is Alice person.DataBackend.ChangeAddress(ref person, newAddress); //person could now be Bob, Eve, or null Could you imagine walking into a store to change

I was trying out the new ref returns of C#7. I am able to compile and build this: public ref string MisUseRefReturn(int index) { string[] array = { "a", "b", "c", "d" }; return ref array[index]; //array[2] gets out of scope when this method returns! } According to MSDN: The return value cannot be a local variable in the method that returns it; it must have a scope that is outside the method that returns it. It can be an instance or static field of a class, or it can be an argument passed to the method. Attempting to return a local variable generates compiler error CS8168, "Cannot return local

Suppose I have a Person class and have the following: Person A = new Person("Tom"); Person B = A; Is there a way I can change it so that if I assign a new Person to B , B = new Person("Harry") , A would be referring to the same instance too? I know you can do that in a ref parameter assignment in a function. UPDATE: The feature described here was added to C# 7. The feature you want is called "ref locals" and it is not supported in C#. The CLR does support generating code that contains ref locals, and a few years ago I wrote an experimental version of C# that had the feature you want, just to

Does boxing/unboxing occur when a method accepts an out/ref parameter of a ValueType? For ref Keyword Its already mentioned on MSDN that : Do not confuse the concept of passing by reference with the concept of reference types. The two concepts are not the same. A method parameter can be modified by ref regardless of whether it is a value type or a reference type. There is no boxing of a value type when it is passed by reference. As for out keyword: The out keyword causes arguments to be passed by reference . This is like the ref keyword, except that ref requires that the variable be