4 ms·

Optimises what away exactly?

• pjmlp 4y ago
  The reference counting code that can be proven to be unnecessary, given the execution flow of the code. Rustc doesn't possess such knowledge about library types.
  • dataangel 4y ago
    Rust is capable of eliminating unnecessary count increments and decrements for Rc fairly often. The compiler doesn't usually need specific knowledge -- if there is a +1 and then a -1 LLVM is smart enough to cancel that out on its own. I'd actually be curious to see examples where it doesn't.
    • pjmlp 4y ago
      Me too, because that is the usual hoping the compiler does the right thing, tied to LLVM, and not part of language semantics.
  • buildartefact 4y ago
    I mean, how often are you cloning an Rc? It’s not like c++ where passing a shared_ptr to a function is going to copy it. Most of the time you’re going to move it.
    • pjmlp 4y ago
      In GUI designers, everywhere.