What's the best way to initialize structure field that has no default ctor?
http://dpaste.dzfl.pl/64cd0a3879fa

Also can I avoid "dummy" non-default ctor for Bar?

drug:

> Also can I avoid "dummy" non-default ctor for Bar?

One solution:


struct Foo {
    int foo;

    @disable this();

    this(int foo_) pure nothrow @safe @nogc {
        this.foo = foo_;
    }
}

struct Bar {
    enum arraySize = 3;

    Foo[arraySize] foo = Foo(1);
}

void main() @safe {
    import std.stdio;

    Bar bar;
    bar.writeln;
}


Bye,
bearophile

On 22.01.2015 15:30, bearophile wrote:
> drug:
>
>> Also can I avoid "dummy" non-default ctor for Bar?
>
> One solution:
>
>
> struct Foo {
>      int foo;
>
>      @disable this();
>
>      this(int foo_) pure nothrow @safe @nogc {
>          this.foo = foo_;
>      }
> }
>
> struct Bar {
>      enum arraySize = 3;
>
>      Foo[arraySize] foo = Foo(1);
> }
>
> void main() @safe {
>      import std.stdio;
>
>      Bar bar;
>      bar.writeln;
> }
>
>
> Bye,
> bearophile

Yes, that's what the doctor prescribed. Thank you!

On Thursday, 22 January 2015 at 12:45:53 UTC, drug wrote:
> On 22.01.2015 15:30, bearophile wrote:
>> drug:
>>
>>> Also can I avoid "dummy" non-default ctor for Bar?
>>
>> One solution:
>>
>>
>> struct Foo {
>>     int foo;
>>
>>     @disable this();
>>
>>     this(int foo_) pure nothrow @safe @nogc {
>>         this.foo = foo_;
>>     }
>> }
>>
>> struct Bar {
>>     enum arraySize = 3;
>>
>>     Foo[arraySize] foo = Foo(1);
>> }
>>
>> void main() @safe {
>>     import std.stdio;
>>
>>     Bar bar;
>>     bar.writeln;
>> }
>>
>>
>> Bye,
>> bearophile
>
> Yes, that's what the doctor prescribed. Thank you!

Or you can use block assignment in the constructor.

struct Bar
{
    enum ArraySize = 3;

    Foo[ArraySize] foo;

    this(string dummy) // <== here because compiler demands to initialize field foo
    {
        import std.algorithm: fill;

        //fill(foo[], Foo(0));
        foo[] = Foo(0);   // <== OK
    }
}

Compiler can recognize the block assignment as a construction for the field Bar.foo.

Kenji Hara