On Sunday, 19 May 2013 at 07:32:11 UTC, matovitch wrote:
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...
I think a better syntax would be:
const Vertex opBinary(string op : "+", "-")(const ref Vertex
vertex)
this will save a bit of ambiguity(`op` is a `string`
specialization of `string[]`?)
At any rate, I'm not sure how useful it would be. Operator
overloading code usually fit for a single operator - you usually
write one for each operator:
const Vertex opBinary(string op : "+")(const ref Vertex vertex)
{
Vertex result = this;
result += vertex;
return result;
}
const Vertex opBinary(string op : "-")(const ref Vertex vertex)
{
Vertex result = this;
result -= vertex;
return result;
}
If you want to have several operators in the same method, you can
afford the verbosity of:
const Vertex opBinary(string op)(const ref Vertex vertex)
if (__traits(compiles, mixin("this " ~ op ~ "= vertex;")))
{
Vertex result = *this;
mixin("result" ~ op ~ "= vertex;");
return result;
}
