[Omp] copy constructor vs. operator= when initializing firstprivate variables

[Chunhua Liao]

Hi,
In OpenMP specification 2.5 page 76, line 23, it reads "For class
types, a copy constructor is invoked to perform the initialization".

Could anyone explain:
1. Why do we have this specific requirement of using copy constructor here ?
2. Is it legal for a compiler to use operator= to do the same work?

Thanks.

Chunhua Liao