Constrained Templates

[BCS]

Hello Ali,


> The method that I learned from Phobos is not the best, but at least
> the function interface reads better:
> 
> T gcd(T)(T a, T b)
> if (supports_modulus!T)
> {
> T result;
> // ...
> return result;
> }
> That makes it clear that T must support the modulus operation.
> 
> Here is how supports_modulus may be defined:
> 
> template supports_modulus(T)
> {
> const bool supports_modulus = is (typeof(
> {
> T a;
> T b;
> T c = a % b;
> }()));
> }

this shorter vertion also works:

template supports_modulus(T)
{
const bool supports_modulus = is (typeof(T.init%T.init) == T);
}

-- 
... <IXOYE><