Re: Create custom data types

[Dennis Ritchie via Digitalmars-d-learn]

On Wednesday, 29 April 2015 at 17:52:27 UTC, Ali Çehreli wrote:

On 04/29/2015 10:17 AM, Dennis Ritchie wrote:

Hi,

Is it possible to create simple D user-defined data types without the

use of classes and other OOP?

For example, in Ada is done as follows:

-----
type balance is new Integer range -32_000 .. 32_000;

Something similar to the following solution should be in Phobos:

import std.exception;

struct Balance
{
    int value_;

    alias value this;

    @property int value() const
    {
        enforce((value_ >= -32_000) &&
                (value_ <=  32_000));

        return value_;
    }

    @property void value(int v)
    {
        value_ = v;
    }
}

unittest
{
    auto b = Balance(42);
    assert(b == 42);

    b = 40_000;

    void foo(int) {}
    assertThrown(foo(b));
}

void main()
{}

Thanks.

On Wednesday, 29 April 2015 at 17:52:27 UTC, Ali Çehreli wrote:

It should be easy to make a template of it. (I really think it should already be in Phobos. :) )

Where can I find documentation on this subject?