mirror of
https://github.com/nlohmann/json.git
synced 2026-10-03 05:00:30 +00:00
Niels Lohmann
08dcdaf9b8
- 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>
37 lines
1.0 KiB
C++
37 lines
1.0 KiB
C++
#include <iostream>
|
|
#include <nlohmann/json_view.hpp>
|
|
|
|
using json_document = nlohmann::json_document;
|
|
using json_view = nlohmann::json_view;
|
|
|
|
int main()
|
|
{
|
|
// required fields of a service configuration -- at() reports a missing
|
|
// or wrong-typed field with the very same exception basic_json::at()
|
|
// would throw for the equivalent nlohmann::json value, so error
|
|
// handling written against basic_json::at() keeps working unchanged
|
|
json_document config = json_document::parse(R"({"name": "cache", "port": "6379"})");
|
|
const json_view service = config.root();
|
|
|
|
std::cout << service.at("port").materialize().dump() << '\n';
|
|
|
|
try
|
|
{
|
|
// "port" is a string, not an array
|
|
static_cast<void>(service.at("port").at(0));
|
|
}
|
|
catch (const nlohmann::json::type_error& e)
|
|
{
|
|
std::cout << e.what() << '\n';
|
|
}
|
|
|
|
try
|
|
{
|
|
static_cast<void>(service.at("timeout"));
|
|
}
|
|
catch (const nlohmann::json::out_of_range& e)
|
|
{
|
|
std::cout << e.what() << '\n';
|
|
}
|
|
}
|