I have template:

<div
*ngFor="let row of rows"
title="{{ row.text }}"
<span
    [id]="tag.index" + {{ implementor }}
    tabIndex="0">
    {{ row.text }}
</span>

Something like this works with no problem:

[id]="tag.index"

Since I am implementing this template in a few places on the same screen
I need to make id unique. The code above compiles, but the runtime gives this error:

Failed to execute 'setAttribute' on 'Element': '+' is not a valid attribute name.

Any idea how to make it work?

Thanks