On 2010-03-20 00.29, bearophile wrote:
(I am looking for rough corners in D, or in my knowledge of D.)
In this page:
http://www.digitalmars.com/d/2.0/templates-revisited.html
In the section "Template Parameters" there is written:
P:P*, // P must be a pointer type
-----------------
So I have written this D2 program:
template IsPointer1(T) {
enum bool IsPointer1 = is(T : T*);
}
void main() {
int* ptr;
static assert(IsPointer1!(typeof(ptr))); // Err
}
But it asserts, do you know why?
You can do like this:
template IsPointer (T)
{
enum IsPointer = false;
}
template IsPointer (T : T*)
{
enum IsPointer = true;
}
-----------------
Then I have written a different program:
template IsPointer2(T) {
enum bool IsPointer2 = is(typeof(*T)) || is(T == void*);
}
void main() {
int* ptr;
static assert(IsPointer2!(typeof(ptr))); // OK
int[] arr;
static assert(!IsPointer2!(typeof(arr))); // Err
}
Do you know why IsPointer2 is true for the dynamic array type too?
(I know in std.traits of Phobos 2 there is an isPointer).
Thank you,
bye,
bearophile
