Try this:
```
import std.typecons;
import std.typetuple;
import std.math;
import std.stdio;
auto tie(StoreElements...)(ref StoreElements stores)
{
alias Elements = staticMap!(Unqual, StoreElements);
template toPointer(T)
{
alias toPointer = T*;
}
struct Holder
{
alias StoreElementsPtrs = staticMap!(toPointer, StoreElements);
StoreElementsPtrs storePtrs;
this(ref StoreElements stores)
{
foreach(i, _; StoreElements)
{
storePtrs[i] = &stores[i];
}
}
void opAssign(Tuple!Elements values)
{
foreach(i, _; Elements)
{
*storePtrs[i] = values[i];
}
}
}
return Holder(stores);
}
Tuple!(float, float) sinCos(float n)
{
return tuple(cast(float)sin(n), cast(float)cos(n)); //please note
cast(float)!
}
void main()
{
float s,c;
tie(s,c) = sinCos(3.0f);
writeln(s, " ", c);
}
```
2014-07-08 22:55 GMT+04:00 Meta via Digitalmars-d-learn <
digitalmars-d-learn@puremagic.com>:
> On Tuesday, 8 July 2014 at 18:45:21 UTC, Remo wrote:
>
>> On Tuesday, 8 July 2014 at 18:29:40 UTC, Meta wrote:
>>
>>> On Tuesday, 8 July 2014 at 17:42:00 UTC, Remo wrote:
>>>
>>>>
>>>> How to make something that work like std::tie in D2 ?
>>>>
>>>> Tuple!(float, float) sinCos(float n) {
>>>> return tuple(cast(float)sin(n), cast(float)cos(n)); //please note
>>>> cast(float)!
>>>> }
>>>>
>>>> int main(string[] argv) {
>>>> float s,c;
>>>> tie!(s,c) = sinCos(3.0f);
>>>> }
>>>>
>>>
>>> alias tie = TypeTuple;
>>>
>>> int main(string[] argv)
>>> {
>>> float s,c;
>>> tie!(s,c) = sinCos(3.0f);
>>> }
>>>
>>
>> Thanks !
>> This is easier as I was thinking :)
>> Now I only need to be sure that this do not have unwanted side effects.
>>
>
> It's fine. There's not much to TypeTuple; it's defined like this:
>
> alias TypeTuple(TList...) = alias TypeTuple = TList;
>
> Where TList is any number of... things. Types, variables, values, template
> names, etc. Therefore, `TypeTuple!(s, c)` at a low level it's more or less
> like the following:
>
> float s, c;
>
> s = sinCos(3.0f)[0];
> c = sinCos(3.0f)[1];
>
> Not that sinCos is called twice. It's only called once, and the result is
> distributed across s and c.
>
