template specialization question

[daoryn]

Daniel Murphy Wrote:

> daoryn Wrote:
> 
> > According to http://digitalmars.com/d/2.0/template.html it is possible to specify template specialization so that DMD prefers them when instanciating templates, however the following code:
> > 
> > 
> > ---------------------------------
> > import std.stdio;
> > 
> > void print(T)(T thing)
> > {
> > 	writeln("Calling print(T)");
> > 	writeln(T.stringof);
> > }
> > 
> > void print(T:T[])(T[] things)
> > {
> > 	writeln("Calling print(T[])");
> > 	writeln(T.stringof);
> > }
> > 
> > void main()
> > {
> > 	print(3);
> > 	print([1,2,3]);
> > }
> > 
> > -----------------------------------------
> > 
> > will output:
> > 
> > Calling print(T)
> > int
> > Calling print(T)
> > int[3u]
> > 
> > I expected it to output "calling print(T[])" on the second "print". Would this be a bug or did I misunderstand the template specialization?
> > 
> 
> It looks like the type of the array literal is a static array, not a dynamic one.
> Static arrays can be matched with the following specification:
> void print(T : U[N], U, size_t N)(T things)
> Or you could use the slice operator to transform the static array into a dynamic one.
> eg print([1,2,3][]);
> 

Sadly, your solution doesnt apply. The used template is still the wrong one.

Code:

void print(T)(T thing)
{
	writeln("Calling print(T)");
	writeln(T.stringof);
}

void print(T:T[])(T[] things)
{
	writeln("Calling print(T[])");
	writeln(T.stringof);
}

void main()
{
	print(3);
	print([1,2,3][]);
}


---------------
output:

Calling print(T)
int
Calling print(T)
int[]


NOTE: DMD2.040 used.