Tom Kazimiers: > How can I have a (temporary) dynamic array on stack and make references > to it (no copying)? I successively put integers in an array (but don't > know how much there will be in advance) with an appender!(int[]) and get > the date out with appender.data(). Later on I pass the result to a > method as an "in int[]" parameter. Is that already a reference or will > it be copied? Are there better methods to accomplish this? The method > receiving such an array will not modifiy contents of the array, but only > read from it.
The appender.data() doesn't currently copy data. There is no standard way to put a growable array on the stack. Maybe you can hack it with several successive calls to alloca(), but I have never tried it. There many other solutions, like: - Using a fixed-sized array on the stack, you keep its true length in a variable - The same, with static array - The same with a static gshared array - pre-allocating a "large enough" dynamic array before all the calls to the function that uses them - using a single alloca() when you know how many items you have to append - use a deque data structure that uses a manually-managed pool of blocks of items, that you can concatenate in a linked list or index through a dynamic array of pointers The cuter solution is to simulate a realloc on the stack (to keep a single growable array) with a series of calls to alloca. But I don't know if it works :-) I will try it. Bye, bearophile
