Re: [Swig-devel] more convenient wrapping of std::vector for C#?

[David P. <dpi...@me...>]

> DP> Why would you want List<T> instead of IList<T>?
> 
>  As I tried to explain in my original message, solely for convenience. To do the
> latter you need the intermediate class (implementing IList<T>) which is
> rather alien from C# programmer point of view.

The user can declare his variable as IList<T>, which is not alien. Try this typemap instead if you wish to hide the wrapper:

%typemap(cstype) std::vector<double> "System.Collections.Generic.IList<double>";

Now there is no need to make a copy of the vector. Admittedly, memory management could be an issue in some cases, which is the only real advantage to duplicating the vector<T> as List<T>.

> DP> Returning List<T> is very inefficient, as a copy of the entire list
> DP> must be made.
> 
...
> and then write
> 
> 	List<double> values = vd.GetValuesUpTo(N);
> 	for (int i = 0; i < values.Count; i++)
> 		Console.WriteLine("{0}", values[i]);
> 
> there are no calls to C++ code after the first line.

You assume the user will store the result in a local variable. If he's calling a method() then he likely will, but if the vector is returned from a variable or property, he likely won't.