On Saturday, 5 August 2017 at 18:22:38 UTC, Stefan Koch wrote:
On Saturday, 5 August 2017 at 18:19:05 UTC, Stefan Koch wrote:
On Saturday, 5 August 2017 at 18:17:49 UTC, Simon Bürger wrote:
If a lambda function uses a local variable, that variable is
captured using a hidden this-pointer. But this capturing is
always by reference. Example:
int i = 1;
auto dg = (){ writefln("%s", i); };
i = 2;
dg(); // prints '2'
Is there a way to make the delegate "capture by value" so
that the call prints '1'?
Note that in C++, both variants are available using
[&]() { printf("%d", i); }
and
[=]() { printf("%d", i); }
respectively.
No currently there is not.
and it'd be rather useless I guess.
You want i to be whatever the context i is a the point where
you call the delegate.
Not at the point where you define the delegate.
No, sometimes I want i to be the value it has at the time the
delegate was defined. My actual usecase was more like this:
void delegate()[3] dgs;
for(int i = 0; i < 3; ++i)
dgs[i] = (){writefln("%s", i); };
And I want three different delegates, not three times the same. I
tried the following:
void delegate()[3] dgs;
for(int i = 0; i < 3; ++i)
{
int j = i;
dgs[i] = (){writefln("%s", j); };
}
I thought that 'j' should be considered a new variable each time
around, but sadly it doesn't work.
