Re: What is the stance on partial initializers when declaring

[Jacob Carlborg]

On 2011-07-22 11:56, kenji hara wrote:
I have posted a pull request for library tuple (= alias this tuple)
unpacking somewhere:
https://github.com/D-Programming-Language/dmd/pull/74
(Test code) https://github.com/D-Programming-Language/dmd/pull/74/files#L7R130
This patch allows unpacking tuple following places:
- Non-template function arguments
- Template function arguments
- StructLiteral arguments
- Initializer
- foreach aggregate
- foreach range.front

And I think make enhancement patch allowing tuple declaration like follows:
auto (i, s) = tuple(1, "str");
TypeTuple!(string, int[]) (s, arr) = TypeTuple!("str", [1, 2]);

Syntax:
("auto" | TupleTypeName) "(" Identifier ["," Identifier ...] ")" "="
Initializer ";"

Tuple assignment is already supported in current D like follows:

import std.typetuple : seq = TypeTuple;
void main()
{
   int x, y;
   seq!(x, y) = seq!(1, 2);  // aassign
   assert(x == 1);
   assert(y == 2);
}

I think more language support for tuple assignment is not need.

Kenji Hara


Cool. But it's quite inconsistent that assignment requires "seq" and 
declaration doesn't.

(x, y) = seq!(1, 2);

Would it be possible to allow the above syntax?

--
/Jacob Carlborg