On 18.03.2012 15:34, Derek wrote:
On Sun, 18 Mar 2012 22:00:06 +1100, Derek <ddparn...@bigpond.com> wrote:
The 'adding' is not the point; it could be any functionality. The
point I was trying to get across was that it would be useful if the
compiler could infer the type parameters of a template instantiation
from the types of the data items used in the instantiation reference.
The best I can come up with so far is ...
[snip]
Why not this:
template add(X)
{
auto add(Y,Z)(Y a, Z b)
{
return cast(X)a + cast(X)b;
}
}
void main()
{
double s;
int t;
ulong u;
s = 1.23;
t = 123;
u = 456;
writeln(add!int(u,s)); // --> 467
writeln(add!double(t,s)); // --> 124.23
}
In short: use type parameters when you parametrize on types. Use IFTI to
avoid typing parameters that could be inferred. X type you cast to,
clearly can't be inferred from arguments.
It seems that the templated function's return type is not used when
searching for matching templates, so I have to explicitly include
something in the function's signature just to use it as the returned
data's type.
No just provide type, dummy values smack of flawed dispatch techniques
from C++ STL.
--
Dmitry Olshansky
