bearophile wrote:
Don:
CTFE is almost completely isolated from the rest of the compiler: it can't break
anything that's not CTFE.<
It's like having a compiler plus a D1 interpreter. In theory this duplication
looks silly, in practice it seems handy.
Interestingly, by *requiring* the compiler to provide an interpreter,
the language can make optimisation guarantees about constant folding,
_independent of the backend_.
It is likely, for example, that unions will need to be disallowed in CTFE,<
Can you tell me why?
Suppose you have:
align(2):
struct S
{
char d;
int a;
char [2] b;
}
union U {
byte[5] a;
double x;
S c;
}
and you write to u.c.d, and u.a[3] what value is x? It's disgusting.
Depends on the endianness of the target system, for example.
but there's absolutely no reason why 'new' expressions should be disallowed.<
I mean things like:
int [] a = new int[n];
which is trivial -- about 5 lines of code.
Oh. And the D1 spec doesn't disallow inline asm in CTFE.
But CTFE asm is Not Going To Happen. <g>
