If I define a non-default constructor for a struct, are the fields initialized to T.init by the time it's called? or am I responsible for initializing all fields in that constructor?

..or do structs follow the same rules as classes?
https://dlang.org/spec/class.html#field-init

  Thanks

On Wednesday, 16 August 2017 at 18:11:05 UTC, bitwise wrote:
> If I define a non-default constructor for a struct, are the fields initialized to T.init by the time it's called?

The struct instance is initialized with T.init before invoking the constructor.

On Wednesday, 16 August 2017 at 18:11:05 UTC, bitwise wrote:
> [...]

I'm asking this because I need to forward args to a container's node's value.

Something like this:


struct Node(T)
{
    int flags;
    T value; // maybe const

    this(Args...)(int flags, auto ref Args args)
    {
        this.flags = flags;

        // this?
        emplace(&value, args);

        // or this?
        value = T(args);

        // ?
    }
}

struct Container(T)
{
    Node!T[] nodes;

    void add(Args...)(auto ref Args args)
    {
        int flags = 1234;
        auto p = cast(Node!T*)malloc(Node!T.sizeof);
        nodes ~= emplace(p, flags, args);
    }
}

On Wednesday, 16 August 2017 at 18:17:36 UTC, kinke wrote:
> On Wednesday, 16 August 2017 at 18:11:05 UTC, bitwise wrote:
>> If I define a non-default constructor for a struct, are the fields initialized to T.init by the time it's called?
>
> The struct instance is initialized with T.init before invoking the constructor.

Thanks for the quick response.

In regards to my second question, the "value = T(args);" variant seems to work, even with a const T, without calling a postblit - so I guess that's what I'll use.