Hi all,
I must overlook something, but
given this:

´´´
void main(){}

static assert(isMatching!(D, S!(D, true))); // place 1: works as expected.

struct D
{
        auto static s = S!(typeof(this), true).init;
}

enum bool isMatching(T, U) =
        (){
                bool b;
                static foreach(i, m; __traits(allMembers, T))
                {
static if(is(typeof(__traits(getMember, T, m)) == U))
                        {
                               if(b) return false;
                               else b = true;
                        }
                }
                return b;
        }();

struct S(T, bool c = false)
        //if(isMatching!(T, S!(T, true))) // place 2: does not work
{}
´´´

While "place 1" works as expected: it static asserts to true, if type D has a single coinciding member to the checked one and static asserts to false if it doesn't or if there are more of them then one;
Why I can't use the same template in "place 2"?


PS: Taken the (){}() pattern from here:
https://p0nce.github.io/d-idioms/#Precomputed-tables-at-compile-time-through-CTFE

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