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Re: std::format and json objects

From: Jason McKesson <jmckesson_at_[hidden]>
Date: Tue, 18 Apr 2023 08:32:32 -0400
On Tue, Apr 18, 2023 at 7:53 AM Federico Kircheis via Std-Discussion
<std-discussion_at_[hidden]> wrote:
>
> Hello, I have a question regarding std::format.
>
> The API works generally very well, but it is problematic to escape every
> { and }, especially when there are a lot of those, like in json objects.
>
> Suppose I have for example the literal
>
> R"json({
> "data": {
> "data 1": [
> {"id":1,"name":"foo"},
> {"id":2,"name":"bar"}
> ],
> "data 2": {"id":2,"name":"____"}
> },
> "otherstuff": {
> "void": [[1,42],[-1,____]]
> }
> })json"
>
> And I would like to use std::format for replacing ____ with some values.
>
> As far as I know, it is not possible to instruct std::format to use
> another pair of delimiters for a single call.
>
> Falling back to std::printf or std::cout does not seem to be the right
> solution, and escaping every { and } has drawbacks too.
>
> Was this issue ever discussed or acknowledged?
> Are there some obvious workarounds I'm missing?

No tool is going to be perfect for every application, and for basic
tools like `format`, you have to pick *something* for your delimiter.

Find/replace is not `format`'s job. That's the job of a regex tool.

Received on 2023-04-18 12:32:44