Building JSON until 2.067

[Matt Kline via Digitalmars-d]

I'm trying to build a small utility for a project at work that 
stores some config on-disk as JSON. Imagine my dismay when I find 
that opIndexAssign hasn't been added to JSONValue until after 
2.066 went out:
https://github.com/D-Programming-Language/phobos/pull/2607

1. Is there any way until 2.067 gets release to build a JSON 
object,
    besides building it as a string?

2. I'm thoroughly confused - something like this would make it 
seem that
    std.json is almost never used "in the wild".
    Is there a JSON library that most other people are using 
instead?