On Thursday, 20 March 2014 at 19:38:25 UTC, Chris wrote:
I thought the array T[] traits could hold any _type_ the
template Trait is instantiated into. That's where I got it
wrong.
This is the best explanation for this restriction that I can
think of:
struct Person(T)
{
static if (is(T == int))
{
int age;
@property int age() { return age; }
@property int age(int val) { return age = val; }
@property bool isMiddleAge() { return age >= 30 && age <=
50); }
}
else static if (is(T == string))
{
string name;
//Etc...
}
}
Depending on what type T is, Person could have an age and
associated methods, or a name and associated methods, but never
both. If T is neither int nor string, it will completely empty.
Therefore, Person!int MUST be a completely different type from
Person!string or Person!float. It just doesn't make any sense
otherwise.
