I have a custom post type 'course', which I'm displaying on my main blog page along with the normal posts.
However, when viewing a single 'post' or 'course', I want the next/previous links to be combined (i.e. to link to either post or course, whichever comes next).
This feels like it should be obvious but can't work it out so far...
I realise there is a plugin (Next/Previous Post Link Plus) which looks like it might do the job, but would prefer to avoid using a plugin for this if possible.