mirror of
https://github.com/nlohmann/json.git
synced 2026-10-01 14:35:18 +00:00
2f087c6b73
- API pages for operator[], at, front, back, find, contains, count, begin, end, cbegin, cend, items, and type_name of basic_json_view, linked both ways with the basic_json pages - the feature page and size() describe document order and duplicate keys - the examples show when the view helps: reading a few fields of a large text, probing optional members, and members in source order Signed-off-by: Niels Lohmann <mail@nlohmann.me>
31 lines
819 B
C++
31 lines
819 B
C++
#include <iostream>
|
|
#include <nlohmann/json_view.hpp>
|
|
|
|
using json_document = nlohmann::json_document;
|
|
|
|
int main()
|
|
{
|
|
// count how many of many incoming records carry an optional "retry_of"
|
|
// field -- contains() only walks the flat index, so scanning a large
|
|
// batch like this never builds a single nlohmann::json value
|
|
json_document batch = json_document::parse(R"(
|
|
[
|
|
{"id": 1},
|
|
{"id": 2, "retry_of": 1},
|
|
{"id": 3},
|
|
{"id": 4, "retry_of": 3}
|
|
]
|
|
)");
|
|
|
|
const auto records = batch.root();
|
|
std::size_t retries = 0;
|
|
for (std::size_t i = 0; i < records.size(); ++i)
|
|
{
|
|
if (records[i].contains("retry_of"))
|
|
{
|
|
++retries;
|
|
}
|
|
}
|
|
std::cout << retries << " of " << records.size() << " records are retries\n";
|
|
}
|