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29cd970b94
* 🔥 consolidate documentation * ♻️ overwork std specializations * 🚚 move images files to mkdocs * ♻️ fix URLs * 🔧 tweak MkDocs configuration * 🔧 add namespaces * 📝 document deprecations * 📝 document documentation generation * 🚸 improve search * 🚸 add examples * 🚧 start adding documentation for macros * 📝 add note for https://github.com/nlohmann/json/issues/874#issuecomment-1001699139 * 📝 overwork example handling * 📝 fix Markdown tables
80 lines
1.9 KiB
C++
80 lines
1.9 KiB
C++
#include <iostream>
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#include <nlohmann/json.hpp>
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using json = nlohmann::json;
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int main()
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{
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// create a JSON value
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const json j =
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{
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{"number", 1}, {"string", "foo"}, {"array", {1, 2}}
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};
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// read-only access
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// output element with JSON pointer "/number"
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std::cout << j.at("/number"_json_pointer) << '\n';
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// output element with JSON pointer "/string"
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std::cout << j.at("/string"_json_pointer) << '\n';
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// output element with JSON pointer "/array"
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std::cout << j.at("/array"_json_pointer) << '\n';
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// output element with JSON pointer "/array/1"
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std::cout << j.at("/array/1"_json_pointer) << '\n';
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// out_of_range.109
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try
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{
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// try to use an array index that is not a number
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json::const_reference ref = j.at("/array/one"_json_pointer);
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}
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catch (json::parse_error& e)
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{
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std::cout << e.what() << '\n';
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}
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// out_of_range.401
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try
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{
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// try to use an invalid array index
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json::const_reference ref = j.at("/array/4"_json_pointer);
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}
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catch (json::out_of_range& e)
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{
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std::cout << e.what() << '\n';
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}
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// out_of_range.402
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try
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{
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// try to use the array index '-'
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json::const_reference ref = j.at("/array/-"_json_pointer);
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}
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catch (json::out_of_range& e)
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{
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std::cout << e.what() << '\n';
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}
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// out_of_range.403
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try
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{
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// try to use a JSON pointer to a nonexistent object key
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json::const_reference ref = j.at("/foo"_json_pointer);
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}
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catch (json::out_of_range& e)
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{
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std::cout << e.what() << '\n';
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}
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// out_of_range.404
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try
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{
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// try to use a JSON pointer that cannot be resolved
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json::const_reference ref = j.at("/number/foo"_json_pointer);
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}
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catch (json::out_of_range& 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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