On Friday, 6 September 2013 at 13:30:26 UTC, Dicebot wrote:
So, what essentially is needed, is ability to implicitly
convert literals of built-in types to user types, not any
possible implicit conversion?
I think allowing it with such restrictions can be reasonably
clean.
Yes, the ability to implicitly convert literals of built-in types
to user types is REALLY needed.
The 2-nd error from "factorial" example
import std.bigint;
void main()
{
assert(factorial!BigInt(BigInt(3)) == 6); //Error:
incompatible types for ((1) :
(number.opBinary(factorial(number.opBinary(1))))): 'int' and
'BigInt'
}
The correct factorial implementation is:
T factorial(T)(T number)
{
enum T one = 1;
return number <= one ? one : number * factorial!T(number -
one);
}
It's complicated, how do you think?
not any possible implicit conversion?
I didn't think about yet. May be you are right, but I think it
can be also useful. For example, if you can't change user-defined
type.
