mirror of
https://github.com/nlohmann/json.git
synced 2026-09-04 15:35:01 +00:00
63 lines
2.2 KiB
C++
63 lines
2.2 KiB
C++
// __ _____ _____ _____
|
|
// __| | __| | | | JSON for Modern C++ (supporting code)
|
|
// | | |__ | | | | | | version 3.12.0
|
|
// |_____|_____|_____|_|___| https://github.com/nlohmann/json
|
|
//
|
|
// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
|
|
// SPDX-License-Identifier: MIT
|
|
|
|
import nlohmann.json;
|
|
|
|
#include <sstream>
|
|
#include <string>
|
|
|
|
using namespace nlohmann::literals;
|
|
|
|
// This test exercises the surface exported by the nlohmann.json module so that
|
|
// a missing or broken export is caught at compile time.
|
|
//
|
|
// NOTE: It is only built with Clang. GCC's C++20 modules implementation (as of
|
|
// GCC 16.1) cannot compile non-trivial use of the imported module: any standard
|
|
// library facility reached through the module triggers redefinition or missing
|
|
// include errors in libstdc++ (and using `import` together with textual
|
|
// `#include`s of standard headers fails as well). The ci_module_cpp20 job is
|
|
// therefore restricted to Clang until GCC's modules support matures.
|
|
int main()
|
|
{
|
|
// basic_json / json: parsing and value access
|
|
nlohmann::json j = nlohmann::json::parse(R"({"a": 1, "list": [1, 2, 3]})");
|
|
const int a = j["a"].get<int>();
|
|
|
|
// json_pointer and operator""_json_pointer
|
|
nlohmann::json_pointer<std::string> ptr = "/list/2"_json_pointer;
|
|
const int last = j[ptr].get<int>();
|
|
|
|
// operator""_json literal
|
|
const nlohmann::json lit = R"([1, 2, 3])"_json;
|
|
|
|
// ordered_json
|
|
nlohmann::ordered_json oj;
|
|
oj["b"] = 2;
|
|
const int b = oj["b"].get<int>();
|
|
|
|
// ordered_map alias
|
|
nlohmann::ordered_map<std::string, int> m;
|
|
m["x"] = 1;
|
|
|
|
// adl_serializer (reference the exported template)
|
|
using serializer = nlohmann::adl_serializer<int, void>;
|
|
static_cast<void>(sizeof(serializer));
|
|
|
|
// to_string
|
|
const std::string dumped = nlohmann::to_string(j);
|
|
|
|
// operator<< (hidden friend, reached via ADL through the module)
|
|
std::ostringstream os;
|
|
os << j << oj << lit;
|
|
|
|
// use every result so the references cannot be optimized away
|
|
return (a == 1 && last == 3 && b == 2 && lit.size() == 3
|
|
&& m.size() == 1 && !dumped.empty() && !os.str().empty())
|
|
? 0 : 1;
|
|
}
|