Hello from France everyone ! (I hope my english will be
readable...)
Yesterday, I discover D and that was really really great. I am
far from being a guru (it seems there are a lot here ;-) but I
foud the language clear and expressive the documentation is very
well done futhermore dmd is incredibly fast and the logs are pure
awesomness (a gcc command often doesn't fit on my shell). I know
you are waiting for a 'but' and there is one : it's about
operators overloading. First, but that kind of ok with me, I
don't like the syntax :
const Vertex opBinary(string op)(const ref Vertex vertex)
if (op == "+" || op == "-")
{
Vertex result = *this;
mixin("result" ~ op ~ "= vertex;");
return result;
}
I don't like the 'if' outside and the condition could be really
long : if (op == "+" || op == "-" || op == "*" || op == "/").
Okay, putting the if inside is quite easy :
const Vertex opBinary(string op)(const ref Vertex vertex)
{
static if if (op == "+" || op == "-")
{
Vertex result = *this;
mixin("result" ~ op ~ "= vertex;");
return result;
}
}
But...I'd like to define cross product :
const T opBinary(string op)(const ref Vertex vertex)
{
static if (op == "*")
{
T result = 0;
foreach(i; 0..vertex_size)
result += coordinate[i] * vertex.coordinate[i];
return result;
}
}
The compiler is not so great here and doesn't distinguish the two
opBinary by their signatures. Why ? Before looking at the
documentation again I tried something like that :
const Vertex opBinary(string op : ["+", "-"])(const ref Vertex
vertex)
{
{
Vertex result = *this;
mixin("result" ~ op ~ "= vertex;");
return result;
}
}
const T opBinary(string op : "*")(const ref Vertex vertex)
{
T result = 0;
foreach(i; 0..vertex_size)
result += coordinate[i] * vertex.coordinate[i];
return result;
}
The second one is okay, but the fisrt one isn't correct. I think
this kind of template specialization over a list could be great
with mixins and static if/switch. What do you think ? May be
there is an other way to do what I want...
