Re: How can convert the folowing to D.

[learner via Digitalmars-d-learn]

On Friday, 1 April 2016 at 01:09:32 UTC, Ali Çehreli wrote:

On 03/31/2016 05:34 PM, learner wrote:

Hi,

I have the following code in C++.

rectangles.erase(rectangles.begin() + index);

where rectangles is:
std::vector<Rectangle> rectangles;

how can I do something similar in D.

Learner.

import std.stdio;

void main() {
    int[] a = [ 1, 2, 3, 4, 5 ];
    writefln("Before: %s", a);
    size_t index = 2;
    a = a[index .. $];       // <-- HERE
    writefln("After : %s", a);
}

Note that it's a cheap operation; the elements are still in memory and not destroyed. If you want to run their destructors you can call destroy() explicitly:

import std.stdio;
import std.algorithm;
import std.range;

struct Rect {
    int i;

    ~this() {
        writefln("Destroying %s", i);
    }
}

void main() {
    Rect[] a = iota(5).map!(i => Rect(i)).array;

    writefln("Before: %s", a);

    size_t index = 2;

    // If you need to run the destructors now:
    a[0 .. index].each!((ref e) => e.destroy);

    a = a[index .. $];

    writefln("After : %s", a);
}

Prints

Destroying 0
Destroying 1
Destroying 2
Destroying 3
Destroying 4
Before: [Rect(0), Rect(1), Rect(2), Rect(3), Rect(4)]
Destroying 0
Destroying 1
After : [Rect(2), Rect(3), Rect(4)]

Ali

thanks