Re: Template Trick

[Ali Çehreli]

On 06/12/2013 02:47 PM, matovitch wrote:

To be more precise the code below doesn't compile :

struct Vector(T, uint N)
{
     alias T type;
     enum dimension = N;
     T data[N];
}

void func(V, V.type def_val) (uint i, V v)
{
     if (i < v.dimension) {
         v.data[i] = def_val;
     }
}

void main()
{
     alias Vector!(int, 3) Vec3i;
     Vec3i v;
     func!(Vec3i, 42)(2, v);
}

With the error message :

test.d(8): Error: no property 'type' for type 'V'
test.d(8): Error: V.type is used as a type

Here is one way:

void func(V, alias def_val) (uint i, V v)
    if (is (typeof(def_val == V.type)))
{
    if (i < v.dimension) {
        v.data[i] = def_val;
    }
}

Ali