Re: I don't quite get foreach ref

[Steven Schveighoffer]

On Sun, 08 Aug 2010 06:01:20 -0400, Tomek Sowiński <j...@ask.me> wrote:
struct DumbRange {
    int front() { return 5; }             // rvalue
    void popFront() { --counter; }
    bool empty() { return counter > 0; }
    uint counter = 10;
}

void clear(ref int a) { a = 0; }

void main() {
    auto r = DumbRange();

    // Doesn't compile (and good): r.front() is not an lvalue
    clear(r.front);

    // Confusingly has no effect. Yet, compiles -- should it?
    foreach(ref a; r) a = 0;
}

I don't know what to make of it, the D page says nothing on foreach ref  
on rvalues.

Historically, when using opApply to implement foreach, opApply's delegate  
must take all ref arguments.  This is a source of pain because if you  
don't want to ref your data, you had to make temporary copies.

I don't know why ranges have propagated this silliness.

You should file a bug.  Also vote for mine:  
http://d.puremagic.com/issues/show_bug.cgi?id=2443

-Steve