Passing a single tuple or multiple values

[John via Digitalmars-d-learn]

On Tuesday, 19 July 2016 at 01:22:01 UTC, jmh530 wrote:
> import std.typecons : isTuple, tuple;
> import std.stdio : writeln;
>
> auto foo(T...)(T x)
> {
> 	T[0] y;
> 	foreach (i, e; x)
> 	{
> 		y += e;
> 	}
> 	return y;
> }
>
> auto bar(T)(T x)
> {
> 	static if (isTuple!T)
> 	{
> 		return foo(x.expand);
> 	}
> }
>
> auto bar(T...)(T x)
> {
> 	return foo(x);
> }

auto bar(T...)(T x)
{
   static if (T.length == 1 && isTuple!(T[0]))
     return foo(x.expand);
   else
     return foo(x);
}

>
> void main()
> {
> 	auto x = tuple(1, 2);
> 	auto y = bar(x);
> 	auto z = bar(x.expand);
> 	writeln(y);
> 	writeln(z);
> }