`std::vector` is often said to be the default container, because it provides good baseline performance for common operations. Recently, I experimented with a simple API change that can improve the performance of a common usage pattern by 10+ %.
  • robinm@programming.dev
    0·
    1 year ago

    Couldn’t this be solved by having push_back being an inline function (or at least the check on capacity being inlined and the rest of the non-trivial part being in a sub non-inline function)?

    • kornel@programming.dev
      1·
      1 year ago

      I don’t know about C++, but in Rust the push is inline, and still doesn’t always optimize checks away due to an annoying edge case: integer overflow. Reserving (old_len + new_len) could give you a smaller buffer than new_len. The optimizer sees it and is pedantic about it.