Re: `this` template params for struct not expressing constness.

[Simen Kjærås via Digitalmars-d-learn]

On Monday, 8 June 2020 at 07:35:12 UTC, adnan338 wrote:
    Self* searchTree(this Self)(auto in ref T item) const {
        if (&this is null)
            return null;
        if (this.item == item)
            return &this;
        return (this.item < item) ?
            this.right.searchTree(item) :
            this.right.searchTree(item);
    }

This method is const, which means 'this' is const, while Self is 
not. What you're looking for here is inout 
(https://dlang.org/spec/function.html#inout-functions):

    auto searchTree()(auto in ref T item) inout {
        if (&this is null)
            return null;
        if (this.item == item)
            return &this;
        return (this.item < item) ?
            this.right.searchTree(item) :
            this.right.searchTree(item);
    }

--
  Simen