This doesn't seem quite right. The asm block case is equivalent to adding a volatile qualifier to the pointer. If you add this qualifier then `std::launder` pro

This doesn't seem quite right. The asm block case is equivalent to adding a volatile qualifier to the pointer. If you add this qualifier then `std::launder` produces the same codegen. I think the subtle semantic distinction is that `volatile` is a current property of the type whereas `std::launder` only indicates that it was a former property not visible in the current scope. Within the scope of that trivial function in which the pointer is not volatile, the behavior of `std::launder` is what I'd expect. The practical effect is to limit value propagation of types marked `const` in that memory. Or at least this is my understanding. DMA memory (and a type residing therein) is often only operationally volatile within narrow, controlled windows of time. The rest of the time you really don't want that volatile qualifier to follow those types around the code.