resize(...)?

[phyz777]

Hello,

is there a resize() function for arrays, analogous to the resize function of std::vector?

[phyz777]

The following piece of code does not compile, which leads me to the suggestion that currently, this function is not implemented:

#include <iostream>
#include "json.hpp"

int main(int argc, char const *argv[]) {
    nlohmann::json j;

    j["array"] = nlohmann::json::array();

    j["array"].resize(5);

    return 0;
}

Is there another efficient way to store a std::vector in an nlohmann::json::array?
Looping and repeatedly invoking push_back will lead to frequent memory re-allocations in the case of large objects.
In this case, a previous call to j["array"].resize(myVector.size()) would lead to a great performance gain.

Thus, I would suggest implementing the two resize functions analogously to the STL.

[nlohmann]

The library itself does not have a resize() function, but you can access the vector inside a json array with get_ref where you can call std::vector::resize on.

[nlohmann]

@phyz777 Does this solve your issue?

[phyz777]

Yepp, works fine! Thanks for linking the get_ref<T>() documentation, that helped a lot.

[nlohmann]

Cool!