c++ - What's the difference between span and array_view in the gsl library?

Question

In several recent conference presentation I've heard Bjarne Stroustrup and others mention new coding guidelines for C++ and some types supporting them.

Specifically, I remember the example of span<T> instead of (T* p, int n) as a parameter to a function (at time about 32:00 into the talk); but I also remember the suggestion to use array_view<T>. Are they two alternatives but the same concept? Or am I confusing things and they're actually not so related?

I can't seem to find any authoritative definition of what they're both supposed to be about.

Answer 1

We talked with people in the library working group in the standards committee. They wanted the array_view they are trying to get into the standard to be read only. For the core guidelines, we needed an abstraction that was read and write. To avoid a clash between the (potential) standards and the guidelines support library (GSL), we renamed our (read and write) array_view to span: https://github.com/microsoft/gsl .