Re: New feature proposal: "initialization scope"

[Ali Çehreli]

On 05/16/2013 03:20 AM, bearophile wrote:

TommiT:

If I needed to initialize only one const variable, I could use a lambda:

const string[100] int__str = {
    string[100] tmp;
    // ... init tmp ...
    return tmp;
}();

...But I can't see any easy solution for initializing two or more
const variables at the same time.

Once we have a tuple unpacking syntax, you return and assign to two
const variables at the same time.

Bye,
bearophile

Until then, we have to define a local Tuple variable ('vars' below):

import std.conv;
import std.typecons;

void foo(size_t N)()
{
    auto init() {
        string[N] int__str;
        int[string] str__int;

        foreach (i; 0 .. N) {
            auto str = to!string(i);
            int__str[i] = str;
            str__int[str] = to!int(i);
        }

        return tuple(int__str, str__int);
    }

    const vars = init();

    const string[N] int__str = vars[0];
    const int[string] str__int = vars[1];
}

void main()
{
    foo!100();
}

Ali