Feature request: show substitution failures

[eyalroz]

It would be nice if cppinsights could print what items in an overload set were rejected due to substitution failure (for illustrating how SFINAE constructs work).

[andreasfertig]

Hello @eyalroz,

interesting idea. I don' know whether that is possible.

Let's assume it would be possible. How would you like them to be presented? What makes template errors so annoying is the compiler telling us all the overloads it tried.

Best,

Andreas

[eyalroz]

Well, initially, and assuming this would possible, I would just like the signatures of the overload-set members for which substitution failed, without listing the failure reason. Remember that the annoying long warning messages are mostly due to showing the entire instantiation "stack" down to where the actual failure occurred. If you only show the outer-level, it should be less painful to go through. But it would be quite useful for debugging template programming issues! Plus, it's part of how your project presents itself: "the magic the compiler does for us to make things work." - sometimes the magic can get somewhat verbose.

[stale]

Thanks for contributing to this issue. As it has been 60 days since the last activity waiting for a followup. This issue will be automatically closed in 7 days, if no further activity occurs. This is often because the request was already solved in some way and it just wasn't updated or it's no longer applicable. If that's not the case, please respond before the issue is closed. We'll gladly take a look again! In any case, thank you for your contributions!

[eyalroz]

That doesn't seem fair.

[andreasfertig]

Hello @eyalroz,

yes, sorry I forgot to remove the tag.

Anyhow, so far I haven't found a way getting this overload set.

Andreas

[andreasfertig]

Hello @eyalroz,

I still haven't found a way to get this overload set. I'm closing this issue now. If anybody has an implementation, I'm happy to reopen it.

Andreas