• Andrej Mitrovic <andrej.mitrovich gmail.com> Jun 18 2012
• "Kenji Hara" <k.hara.pg gmail.com> Jun 18 2012

Andrej Mitrovic <andrej.mitrovich gmail.com> writes:

struct Wrap
{
    string wrap;
    alias wrap this;
}

void main()
{
    Wrap x;
    x = "foo";  // ok
    Wrap[] y = ["foo", "bar"];  // fail
}

Error: cannot implicitly convert expression (["foo","bar"]) of type
string[] to Wrap[]

Any special reason why this doesn't work? I hope it's just a bug or
unfinished implementation.

"Kenji Hara" <k.hara.pg gmail.com> writes:

On Monday, 18 June 2012 at 16:51:11 UTC, Andrej Mitrovic wrote:
 struct Wrap
 {
     string wrap;
     alias wrap this;
 }

 void main()
 {
     Wrap x;
     x = "foo";  // ok
     Wrap[] y = ["foo", "bar"];  // fail
 }

 Error: cannot implicitly convert expression (["foo","bar"]) of 
 type
 string[] to Wrap[]

 Any special reason why this doesn't work? I hope it's just a 
 bug or
 unfinished implementation.


This kind conversions should be possible with std.conv.to.

import std.conv;
struct Wrap
{
     string wrap;
     alias wrap this;
}
void main()
{
     Wrap[] y = to!(Wrap[])(["foo", "bar"]);  // shold work
}

If you can construct Wrap object with the syntax Wrap("foo"), 
std.conv.to runs 'conversion by construction'.
And if S is convertible to T, std.conv.to!(T[])(S[] source) runs 
'element-wise array conversion'.
As a result, string[] to Wrap[] will be converted.

...but, this does not work in 2.060head, it is a bug.

Kenji Hara