json array: initialize with prescribed size and `resize` method.

[SylvainCorlay]

Feature Request

I would like the ability to initialize a JSON array with a prescribed size.

My use case if that I know that I will be setting all items of a JSON arrays on known length but out of order.

I could do this with an intermediate STL container but I would prefer to avoid the temporary.

[nlohmann]

You can use this constructor: https://nlohmann.github.io/json/classnlohmann_1_1basic__json_ab6816ae5100409254ed0a8bc21c387bb.html#ab6816ae5100409254ed0a8bc21c387bb

[nlohmann]

@SylvainCorlay Does this solve this issue?

[SylvainCorlay]

yep, closing!

thanks!