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5a9f59a688
- 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>
28 lines
723 B
C++
28 lines
723 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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// scan a (possibly large) array of readings for the first one over a
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// threshold; the loop stops at end() as soon as one is found, and only
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// the matching reading is ever materialized
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json_document readings = json_document::parse("[12, 18, 25, 31, 9]");
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const auto values = readings.root();
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auto it = values.begin();
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for (; it != values.end(); ++it)
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{
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if (it->materialize().get<int>() > 20)
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{
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break;
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}
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}
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if (it != values.end())
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{
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std::cout << "first reading over 20: " << it->materialize().dump() << '\n';
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}
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}
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