nlohmann::basic_json::max_size - renxiaobo27/json GitHub Wiki

size_type max_size() const;

Returns the type-dependent maximum number of elements the JSON container is able to hold due to system or library implementation limitations, i.e. std::distance(begin(), end()) for the largest container.

The return value depends on the different value types and is defined as follows:

None.

Constant, as long as ArrayType and ObjectType satisfy the Container concept.

None. The function's noexcept-specification is noexcept.

This value is typically equal to std::numeric_limits<size_type>::max(), and reflects the theoretical limit on the size of the container. At runtime, the size of the container may be limited to a value smaller than max_size() by the amount of RAM available.

#include <iostream>
#include <json.hpp>
 
int main()
{ 
    nlohmann::json array {"string", true, 17, 23.42};
 
    std::cout << "Maximum size of a JSON array is " << array.max_size() << "\n";
}

Output:

Maximum size of a JSON array is 1152921504606846975

• size
  returns the number of elements