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https://github.com/nlohmann/json.git
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Niels Lohmann
08dcdaf9b8
- 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>
30 lines
880 B
C++
30 lines
880 B
C++
#include <iostream>
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#include <nlohmann/json_view.hpp>
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using json_document = nlohmann::json_document;
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int main()
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{
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// validate that every transaction of a batch carries a mandatory
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// "amount" field before materializing any of them into a nlohmann::json
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// value -- count() returns 0 or 1 for an object
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json_document batch = json_document::parse(R"(
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[
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{"id": 1, "amount": 9.99},
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{"id": 2}
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]
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)");
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const auto transactions = batch.root();
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for (std::size_t i = 0; i < transactions.size(); ++i)
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{
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const auto transaction = transactions[i];
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if (transaction.count("amount") == 0)
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{
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std::cout << "transaction " << i << " is missing \"amount\"\n";
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continue;
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}
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std::cout << "transaction " << i << ": " << transaction["amount"].materialize().dump() << '\n';
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}
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}
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