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Niels Lohmann
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>
25 lines
815 B
C++
25 lines
815 B
C++
#include <iostream>
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#include <numeric>
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#include <nlohmann/json_view.hpp>
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using json_document = nlohmann::json_document;
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using json_view = nlohmann::json_view;
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int main()
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{
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// sum many measurements with std::accumulate; cbegin()/cend() (identical
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// to begin()/end() here -- the view is always read-only) let the view be
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// used with standard algorithms without ever materializing the whole
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// array into a nlohmann::json value
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json_document measurements = json_document::parse("[3, 1, 4, 1, 5, 9, 2, 6]");
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const auto values = measurements.root();
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const int sum = std::accumulate(values.cbegin(), values.cend(), 0,
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[](int total, const json_view & v)
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{
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return total + v.materialize().get<int>();
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});
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std::cout << sum << '\n';
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}
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