On Tuesday, 11 April 2017 at 03:00:29 UTC, Jon Degenhardt wrote:
On Tuesday, 11 April 2017 at 01:59:57 UTC, Jonathan M Davis
wrote:
On Tuesday, April 11, 2017 01:42:32 Jethro via
Digitalmars-d-learn wrote:
[...]
You can't reuse the memory of a dynamic array by simply
setting its length to 0. If that were allowed, it would risk
allow dynamic arrays to stomp on each others memory (since
there is no guarantee that there are no other dynamic arrays
referring to the same memory). However, if you know that there
are no other dynamic arrays referrin to the same memory, then
you can call assumeSafeAppend on the dynamic array, and then
the runtime will assume that there are no other dynamic arrays
referring to the same memory.
[snip]
Another technique that works for many cases is to use an
Appender (std.array). Appender supports reserve and clear, the
latter setting the length to zero without reallocating. A
typical use case is an algorithm doing a series of appends,
then setting the length to zero and starts appending again.
--Jon
Appender reports clear? Are you sure?
Seems appender is no different than string, maybe worse? string
as assumeSafeAppend, reserve and clear(although clear necessarily
reallocates. They should have a function called empty, which
resets the length to zero but doesn't reallocate.
