struct S {/* containing anything except reference for class or array */}
struct T {/* containing anything */}
class C {}

void main()
{
	//	invalid initialization is accepted
	S a = T();
	S b = 1;

	//	valid error in compile time : dynamic initilizer of struct
	S c = 1.0;	// cannot cast double to S
	S d = new T;
	S e = new C;
	S f = new int[1];

	//	valid error in compile time : assignment
	a = T();
	b = 1;
}

It seems this problem results from implicit cast in the dynamic initialization of structs.
It is highly severe when both S and T contain only integer type.

In C, any named enum is treated as int.
This problem resembles that.