Re: Is variable void?

[bauss via Digitalmars-d-learn]

On Monday, 27 November 2017 at 02:12:40 UTC, codephantom wrote:

On Saturday, 25 November 2017 at 15:34:21 UTC, John Chapman wrote:

Is there any way of determining whether a variable has been initialized or not? For example, if something is declared like this:

  int x = void;

can I check if it's void before I use it, say, in a function it's been passed to?

// ----------------------------------

module test;

import std.stdio;

import std.typecons; // see: https://dlang.org/phobos/std_typecons.html#Nullable

void main()
{
    Nullable!int x;  // requires: import std.typecons
    assert(x.isNull);
    writeln("x is ", x);

    x = 1;
    assert(!x.isNull);
    writeln("x is ", x);

    x.nullify(); //     Forces x back to a null state.
    assert(x.isNull);
    writeln("x is ", x);

}
// ----------------------------------

null != void