On Saturday, 19 October 2013 at 15:22:31 UTC, Agustin wrote:
I'm trying to implement a template Vector and i would like to
know if this is possible.
My current vector class is:
public class Vector(T, size_t size) {
private T components[size];
}
And i would like to implement a property as this:
@property
public size_t length() const {
return Trait.ExpandFor(size, components, Function(+, (n,
j))); // Kind of messy but you get my point.
}
instead of doing for(...) over a array i would like to make a
trait that produce this code
return (x * x + y * y + z * z + ...)
From your post i guess that the goal here is to do
loop unrolling.
A simple way to achive this is to force a loop unrool
by iterating over a TypeTuple.
module vector;
import std.typetuple;
class Vector(T, size_t size) {
private T[size] components;
public T length() const //Guessing this is vector magnitude
{
T res = 0;
foreach(i; staticIota!(0u, size)) //Unrools the loop at
compile-time.
{
res += components[i];
}
return cast(T)std.math.sqrt(res);
}
}
//Creates a range from start inclusive to end exclusive.
template staticIota(size_t start, size_t end)
{
static if(start == end)
alias TypeTuple!() staticIota;
else static if(start < end)
alias TypeTuple!(start, staticIota!(start + 1, end)) staticIota;
else
static assert(0, "start cannot be greater then end!");
}
This works since the value _size_ is avalible at compile-time.
