On 4/16/18 4:49 AM, Ali Çehreli wrote:
On 04/15/2018 11:46 PM, WhatMeForget wrote:
 >
 > I think I got a handle on D's static and dynamic arrays, till I come to
 > std.array and see all the shiny new tools. I can understand all the
 > replace.. functions, but the appender function gave me pause. The
 > documentation says appender "Returns a new Appender or RefAppender
 > initialized with a given array."

New Appender allocates new memory. If an array is already available for an Appender to use, then it's more efficient.

 > My first thought that doesn't D's built in arrays already allow
 > appending? (at least for dynamic arrays)

Yes but Appender is reported to be faster presumably it uses a different allocation scheme and may be more free compared to dynamic arrays that must play well with GC and its pages.

It's because it stores the relevant information in a local type vs. having to look it up in the GC.

It's also not all opaque calls (they can be inlined).

 > Another thing that had me wondering is the use of put()
 > down below; doesn't the append syntax (~=) give you the same exact
 > functionality; so why bother?

put() is old, ~= is new. Both are supported.


put is required for Appender to be an output range.

-Steve

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