Thanks for the suggestions regarding the `scope` parameter
attribute. I'll look into it!
On Sunday, 21 May 2017 at 01:30:51 UTC, Adam D. Ruppe wrote:
On Sunday, 21 May 2017 at 00:49:23 UTC, Stanislav Blinov wrote:
[...] you *can* write out the struct now, it just has more
tedious syntax.
This exact statement applied to C++ before C++11, but the
introduction of lambda expression significantly changed the way
people write and think about C++. Sometimes syntactic sugar can
have huge impact on a language.
I think that creating anonymous structs on the spot (value type
closures) is not a replacement for the current GC'd closures - it
has a completely different meaning that can be exactly what you
need in particular situations, not only for performance-related
issues. As an example, consider this code:
void delegate()[] arr;
foreach(i; 0..5)
{
arr ~= () => writeln(i);
}
foreach(f; arr)
{
f();
}
This is going to print "4 4 4 4", which might be the desired
behavior. In other occasions you want to create a closure that
captures the outer context by value. Here's some example
pseudocode:
void value_delegate()[] arr;
foreach(i; 0..5)
{
arr ~= [i]() => writeln(i);
}
foreach(f; arr)
{
f();
}
The pseudocode above would explicitly capture `i` by value and
produce a `struct`-like closure. It would print "0 1 2 3".
