On Tuesday, 2 April 2019 at 18:52:07 UTC, Jacob Carlborg wrote:
On 2019-04-02 20:44, Q. Schroll wrote:
After removing the calls to writeln, the error I get is:
`this` for `read` needs to be type `Outer` not type `Inner`
You cannot access stuff in Outer because Inner objects are not
outer objects and don't implicitly own an Outer object. In
your Inner method `write`, there is no Outer object present at
all to call the method on.
It works if the struct is nested inside a function [1]. I
thought it would work nested inside a struct too.
[1] https://dlang.org/spec/struct.html#nested
The reason it works inside a function is that the struct has a
hidden pointer to the function context. The function's local
values actually exist when an object of that struct type is being
instantiated.
The main difference between a struct nested in a function and one
inside another struct is that the one in a function cannot¹ be
created outside of that function while constructing the latter is
possible the way you think it is:
Outer.Inner innerObj = Outer.Inner(parameters);
¹ You can using reflection and stuff like that, but it's still
broken if it uses the context.
