On Wednesday, 19 December 2018 at 19:58:53 UTC, Neia Neutuladh
wrote:
On Wed, 19 Dec 2018 17:28:01 +0000, Vijay Nayar wrote:
Could you please elaborate a little bit more on this? In the
linked program, I had expected that "ref" would return a
reference to "a" that would behave similar to a pointer.
They work like pointers that automatically dereference when
assigning to the base type.
Only three things in D can be ref:
* A function parameter
* A function return value
* A foreach variable (since that's either going to be a
function return
value, a function parameter, or a pointer, depending on what
you're
iterating over)
So when the compiler sees something like:
ref int foo();
auto a = foo();
It sees that the type of 'a' has to be the same as the return
type of 'foo'. Except that's not possible, so it uses the
nearest equivalent type: int.
And if you have:
ref int foo();
int a = foo();
That obviously converts by copying the value.
To be fair even in c++ this won't be a reference.
int& foo();
auto a = foo(); // a == int
auto& a = foo(); // a == int&
So it shouldn't be that surprising.
