Comment 13 for bug 305460

The example in this bug is not as severe and frequent as the one in bug 44841. Users are more likely to encounter this issue when adding a new API to existing interface or type erasure.

Calling this a "well-known issue" is irresponsible. The issue significantly increases the bar to learners to consume and accept new paradigms in the language.

The issue has not been fixed for ten years. It is a shame rather than some arcane knowledge that worth to be proud of.

MSVC has no such issue. The error message reads as "undefined reference to Class::that_virtual_function."

Some possible fixes:

1. Adjust the error message to say, "The first non-inline, non-pure function may not have a definition in <Class>."
2. Add extra information to name the key function, and pass it to the linker, generate an error message to match MSVC's quality.