How to return a const handle (view) to a mutable member of an agregate

[Basile B. via Digitalmars-d-learn]

On Sunday, 13 March 2016 at 19:37:42 UTC, ParticlePeter wrote:
> I have a struct that privately warps an std.container.array. I 
> would like to return a read-only reference of this array, it 
> should not be duplicated. How can I do this?
>
> Cheers, ParticlePeter

ref const(Array!Type) view(){}

Unless the result is explicitly cast later it can't me modified.


import std.stdio, std.container.array;

struct Foo
{
     private Array!int arr;
     ref const(Array!int) view()
     {
         return arr;
     }
}

void main(string[] args)
{
     Foo foo;
     auto a = foo.view.dup;
}