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nlohmann::basic_json_view::cend

iterator cend() const noexcept;

Returns an iterator to one past the last element, in document order. Equivalent to end(): a view is always read-only, so const_iterator and iterator are the same type, and cend() exists only so that generic code that expects a cbegin()/cend() pair works with a view too.

Return value

Iterator one past the last element; identical to what end() returns.

Exception safety

No-throw guarantee: this function never throws exceptions.

Complexity

Constant.

Examples

Example

The example below checks that every record of a batch is an object with std::all_of, using cbegin()/cend() as the range -- the same way it would for any standard container -- before materializing any record of the batch.

#include <algorithm>
#include <iostream>
#include <nlohmann/json_view.hpp>

using json_document = nlohmann::json_document;
using json_view = nlohmann::json_view;

int main()
{
    // check that every element of a (possibly large) batch is an object,
    // before materializing any of them -- cbegin()/cend() (identical to
    // begin()/end() here) work as the range for std::all_of like they would
    // for any standard container
    json_document batch = json_document::parse(R"([{"id": 1}, {"id": 2}, {"id": 3}])");
    const auto records = batch.root();

    const bool all_objects = std::all_of(records.cbegin(), records.cend(),
                                         [](const json_view & v)
    {
        return v.is_object();
    });

    std::cout << std::boolalpha << all_objects << '\n';
}

Output:

true

See also

  • end - returns an iterator to one past the last element
  • cbegin - returns a const iterator to the first element
  • BasicJsonType::cend - the corresponding function of basic_json

Version history

  • Added in version 3.13.0 unreleased.