I've mainly written unusual code that allocates a bunch of FixedBufferAlocators up front and clears each of them according to their own lifecycles. I agree that more typical code would reach for a GPA or something here. If you're using simdjzon, the tape and strings will be allocated contiguously within a pair of buffers (and then if you actually want to copy from the tape to your own struct containing slices or pointers then you'll have to decide where that goes), but the std json stuff will just repeatedly call whatever allocator you give it.
Well, see, the problem is that you’re going to have to keep the allocator alive for the entire lifetime you use any data whatsoever from the JSON. Or clone it manually. Both seem like they largely negate any benefit you get from using it?
