39 lines
1.5 KiB
C++
39 lines
1.5 KiB
C++
#include <iostream>
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#include <nlohmann/json_view.hpp>
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using json = nlohmann::json;
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using json_editable_document = nlohmann::json_editable_document;
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using json_editable_view = nlohmann::json_editable_view;
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int main()
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{
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// a deployment plan -- "budget" is written with a trailing zero that has
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// no effect on its value
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const std::string text = R"({
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"release": "2026.09",
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"steps": ["build", "test", "deploy"],
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"budget": 19.90
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})";
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json_editable_document doc = json_editable_document::parse(text);
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const std::size_t deploy_index = 2;
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const auto deploy = doc.root()["steps"][deploy_index]; // held across the insert
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doc.insert(doc.root()["steps"], deploy_index, "smoke-test"); // insert before "deploy"
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// the held view still refers to "deploy", even though its index moved
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// from 2 to 3, and nothing else in the document was touched
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std::cout << deploy.dump() << '\n';
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std::cout << doc.root().dump(2, ' ', false, json_editable_view::number_format::source) << "\n\n";
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// the same edit on a plain json value: an index held from before the
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// insert now refers to whatever moved into that slot, and dump()
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// rewrites "budget" to its shortest form even though it was never
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// touched
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json plain = json::parse(text);
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plain["steps"].insert(plain["steps"].begin() + static_cast<std::ptrdiff_t>(deploy_index), "smoke-test");
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std::cout << plain["steps"][deploy_index].dump() << '\n';
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std::cout << plain.dump(2) << '\n';
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}
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