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Increasing performance with static polymorphism (and other neat tricks) in D

• srean 13y ago
  scopebuffer seems so useful, why is it hidden in internal ? /* * A destructor is not used, because that would make it not POD * (Plain Old Data) and it could not be placed in registers. * */ Is there a way in D to check at compile time if a type is a POD type ? Strangely enough I had to implement something similar in C++ very recently. I went with a solution that uses alloca if the size is lower than some limit, else falls back to new. I was torn between whether to allocate an array statically or use alloca, eventually went with alloca although that is usually frowned upon. I expected this function to be called from multiple threads not all of which would need to allocate space, using an array on stack would have wasted space. Wish C++ committee approved the proposal to have variable sized arrays like the ones C has now.
  • biotronic 13y ago
    > Is there a way in D to check at compile time if a type is a POD type ? http://dlang.org/phobos/std_traits#hasElaborateDestructor http://dlang.org/phobos/std_traits#hasElaborateDestructor I believe this is what you're looking for. Mayhap you need to combine it with hasElaborateCopyConstructor and/or other functions in std.traits.
  • WalterBright 13y ago
    scopebuffer's inclusion in Phobos was controversial. Many felt that its unusual design (such as lack of destructor), and ease of misuse, meant it shouldn't be there.
    • srean 13y ago
      Can't the destructor issue be mitigated by hasElaborateDestructor( ) that biotronic pointed me to ? EDIT: To clarify, one could have two versions one with a destructor for non POD and the current one. The compiler dispatches to the appropriate one at compile time.
      • WalterBright 13y ago
        No, as that doesn't convert anything to POD.