Re: C89 "bug"

Em 12/13/2024 3:15 PM, Keith Thompson escreveu:

Thiago Adams <thiago.adams@gmail.com> writes:

Does anyone knows how can I convert this code (external declaration) to C89?
>
union U {
     int i;
     double d;
};
>
union U  u = {.d=1.2};
>
The problem is that in C89 only the first member of the union is
initialized.

 The obvious solution is:
     union U u;
     u.d = 1.2;
But that works only if u has automatic storage duration.
 You could also define a function that takes a double argument and
returns a union U result.

Like this?
union U {
     int i;
     double d;
};
union U f(){ union U u; u.d = 1.2; return u;}
union U u = f();
The problem is that f() is not a constant expression for external declarations.