[ericdfoley]

The thing is that there is probably a lot of existing C++ code that is UB without std::launder (similarly to aliasing rules.) The main problem is that the C++ object lifetime rules are not well understood by most people writing C++ code.

[sqeaky]

I hadn't even considered the task of going through old code and using this to make it more compliant, this is a great use case for this feature.