I created a custom visualizer file (.natvis) for Visual Studio (17.7.4) in order to be able to see data inside Armadillo containers.
The custom visualization only works when hovering over the variable and when ReSharper(2018.3.2) is enabled. If I open up the Locals window or add a Watch the custom visualization is not shown (with or without ReSharper being enabled).
According to this post Is there a way to print an Armadillo matrix or vector in Visual Studio Debug? the natvis file is working.
Another related link. customize multi-dimension array debugging in visual studio 2015 with .natvis file
It turns out that the .natvis file was being loaded and parsed correctly according to the natvis diagnostics output. The reason why the custom visualization was only working when hovering over the variable (a ReSharper feature) and not in the output variables window was due to a debugger setting, Debug -> Options -> General -> Show raw structure of objects in variable windows.
I tried implementing the suggestions in this post, namely the part about turning on the "Show raw structure of objects in variable windows" option. As suggested in the post, turning that feature on and off might work. I ended up restarting my computer and set that option to off. This fixed my issues, and I was able to see the custom visualization in the variables window and when hovering over the variable.