Re: assumeSafeAppend on slice of static array?

[Dmitry Olshansky via Digitalmars-d]

22-Apr-2014 22:10, H. S. Teoh via Digitalmars-d пишет:

I'm going through some code and thinking of ways to reduce GC pressure,
and came across a bit that needed to append some items to an array:

        T[] args;
        lex.expect("(");
        args ~= parseSingleItem(lex);
        while (!lex.empty) {
                lex.expect(",");
                args ~= parseSingleItem(lex);
        }
        lex.expect(")");
        return computeResult(args);

Now obviously, in the general case (with arbitrarily many number of
items) some GC allocations will be needed, but the most common use-cases
are actually only 1 or 2 items each time. Allocating lots of small
arrays seem to be rather wasteful, so I thought to use a static array as
a buffer instead.

The question is, is there a way to take a slice of the static array, set
the length to zero, and append to it with ~= such that when it runs out
of space in the static buffer, it will reallocate a longer array on the
GC heap? Or is this a bad idea?

Should be a canonical use case for ScopeBuffer
https://github.com/D-Programming-Language/phobos/blob/master/std/internal/scopebuffer.d

Except that it has crippled usability e.g. you need to call free manually.

--
Dmitry Olshansky