[colalb1]

ProducerConsumerQueue allocates its ring with std::malloc, which only guarantees alignof(std::max_align_t). A T with a stricter alignas is then constructed on misaligned storage. This is undefined behavior, may crash: an alignas(32) __m256d struct built with -mavx2 segfaults on an aligned vmovapd store.

Over-aligned T now uses folly::operator_new and folly::operator_delete with std::align_val_t. Other types keep std::malloc and std::free. There is no change to the public API or object layout. Generated code for ProducerConsumerQueue<long> is identical before and after.