Kenji Hara:
AFAIK, there is no plan for fix. The behavior is currently a part of language design.
Considering matters of D semantic uniformity, and the code shown by Dicebot:
template Hello(T...)
if (T.length == 1)
{
static if (is(T[0]))
// ...
else
// ...
}
Then maybe the current behavior is worth reconsidering.
Bye,
bearophile
