On Wednesday, 3 February 2016 at 18:03:24 UTC, ZombineDev wrote:
C++11 allows you to capture a local variable explicitly by
value.
What is the simplest way to make code below print "0 1 .. 9",
like the C++ version does?
D version:
```
import std.stdio;
void main()
{
alias F = void delegate();
F[] arr;
foreach (i; 0 .. 10)
arr ~= { write(i, " "); };
foreach (f; arr)
f();
}
```
Prints: 9 9 9 9 9 9 9 9 9 9
C++ version:
```
#include <iostream>
#include <functional>
#include <vector>
using namespace std;
int main()
{
using F = function<void()>;
vector<F> arr;
for (auto i = 0; i < 10; ++i)
arr.push_back([=]() { cout << i << " "; });
for (auto f : arr)
f();
}
```
Prints: 0 1 2 3 4 5 6 7 8 9
One stupid solution is to replace `0 .. 10` with staticIota!(0,
10), which would unroll the loop at CT, but I want something
more general that would me allow me to capture the values of a
range while iterating over it at run-time.
I think these two links, more or less, answer my question:
http://stackoverflow.com/questions/29759419/closures-in-loops-capturing-by-reference
https://issues.dlang.org/show_bug.cgi?id=2043
