JSON for Modern C++  3.0.1

◆ is_structured()

template<template< typename, typename, typename... > class ObjectType = std::map, template< typename, typename... > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename > class AllocatorType = std::allocator, template< typename, typename=void > class JSONSerializer = adl_serializer>
constexpr bool nlohmann::basic_json::is_structured ( ) const
inlinenoexcept

This function returns true if and only if the JSON type is structured (array or object).

Returns
true if type is structured (array or object), false otherwise.
Complexity Constant.
Exception safety No-throw guarantee: this member function never throws
exceptions.
Example The following code exemplifies is_structured() for all JSON
types.
1 #include <iostream>
2 #include "json.hpp"
3 
4 using json = nlohmann::json;
5 
6 int main()
7 {
8  // create JSON values
9  json j_null;
10  json j_boolean = true;
11  json j_number_integer = 17;
12  json j_number_float = 23.42;
13  json j_number_unsigned_integer = 12345678987654321u;
14  json j_object = {{"one", 1}, {"two", 2}};
15  json j_array = {1, 2, 4, 8, 16};
16  json j_string = "Hello, world";
17 
18  // call is_structured()
19  std::cout << std::boolalpha;
20  std::cout << j_null.is_structured() << '\n';
21  std::cout << j_boolean.is_structured() << '\n';
22  std::cout << j_number_integer.is_structured() << '\n';
23  std::cout << j_number_unsigned_integer.is_structured() << '\n';
24  std::cout << j_number_float.is_structured() << '\n';
25  std::cout << j_object.is_structured() << '\n';
26  std::cout << j_array.is_structured() << '\n';
27  std::cout << j_string.is_structured() << '\n';
28 }
basic_json<> json
default JSON class
Definition: json.hpp:14379

Output (play with this example online):
false
false
false
false
false
true
true
false

The example code above can be translated with
g++ -std=c++11 -Isrc doc/examples/is_structured.cpp -o is_structured 
See also
is_primitive() – returns whether value is primitive
is_array() – returns whether value is an array
is_object() – returns whether value is an object
Since
version 1.0.0

Definition at line 9189 of file json.hpp.