30 lines
910 B
C++
30 lines
910 B
C++
#include <iostream>
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#include <nlohmann/json_view.hpp>
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#include <string>
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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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json_document doc = json_document::parse(R"({"server": {"host": "localhost"}})");
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const json_view server = doc.root()["server"];
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// "port" is missing -- value() returns the default instead of
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// throwing, so optional configuration fields never need their own
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// try/catch
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std::cout << server.value("host", std::string("0.0.0.0")) << '\n';
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std::cout << server.value("port", 8080) << '\n';
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// a present but wrong-typed default still throws -- value() only
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// replaces "not found", not "wrong type", exactly as basic_json::value
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try
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{
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static_cast<void>(server.value("host", 0));
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}
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catch (const nlohmann::json::type_error& e)
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{
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std::cout << e.what() << '\n';
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}
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}
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