Re: Struct reference returning function and const members

[Tom]

El 03/03/2011 03:47, Ali Çehreli escribió:
On 03/02/2011 10:42 PM, Tom wrote:
I have...
int main(string[] args) {
auto s1 = f(); // MH MH
auto s2 = g(); // OK
s2.c = null; // OK
return 0;
}

class C {}

struct StructWithConstMember {
this(int i, C c) { this.i=i; this.c=c; }
int i;
const(C) c;
}

struct StructWithoutConstMember {
this(int i, C c) { this.i=i; this.c=c; }
int i;
C c;
}

ref StructWithConstMember f() {
return * new StructWithConstMember(1, new C); // ERROR
}

ref StructWithoutConstMember g() {
return * new StructWithoutConstMember(1, new C); // OK
}


And get the error...
src\main.d(27): Error: *new StructWithConstMember(1,new C) is not mutable

So I can't return a struct that has a const member? Why? Am I missing
something something?

Thanks,
Tom;

I don't know the full answer but returning a reference to const object
works:

ref const(StructWithConstMember) f() {
return * new StructWithConstMember(1, new C); // now compiles
}

Ali


I know, but I don't want a const struct. It's like if const transitivity 
were going backwards, or something.

:(