On Saturday, 1 November 2014 at 07:02:03 UTC, Walter Bright wrote:
On 10/30/2014 8:30 AM, Steven Schveighoffer wrote:
This is a typical mechanism that Tango used -- pass in a ref
to a dynamic array
referencing a stack buffer. If it needed to grow, just update
the length, and it
moves to the heap. In most cases, the stack buffer is enough.
But the idea is to
try and minimize the GC allocations, which are performance
killers on the
current platforms.
We keep solving the same problem over and over.
std.internal.scopebuffer does this handily. It's what it was
designed for - it works, it's fast, and it virtually eliminates
the need for heap allocations. Best of all, it's an Output
Range, meaning it fits in with the range design of Phobos.
It is not the same thing as ref/out buffer argument. We have been
running ping-pong comments about it for a several times now. All
std.internal.scopebuffer does is reducing heap allocation count
at cost of stack consumption (and switching to raw malloc for
heap) - it does not change big-O estimate of heap allocations
unless it is used as a buffer argument - at which point it is no
better than plain array.
