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◆ object()
template<template< typename U, typename V, typename... Args > class ObjectType = std::map, template< typename U, typename... Args > 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 U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>
Creates a JSON object value from a given initializer list. The initializer lists elements must be pairs, and their first elements must be strings. If the initializer list is empty, the empty object {} is created.
- Note
- This function is only added for symmetry reasons. In contrast to the related function array(initializer_list_t), there are no cases which can only be expressed by this function. That is, any initializer list init can also be passed to the initializer list constructor basic_json(initializer_list_t, bool, value_t).
- Parameters
-
[in] | init | initializer list to create an object from (optional) |
- Returns
- JSON object value
- Exceptions
-
type_error.301 | if init is not a list of pairs whose first elements are strings. In this case, no object can be created. When such a value is passed to basic_json(initializer_list_t, bool, value_t), an array would have been created from the passed initializer list init. See example below. |
- Complexity
- Linear in the size of init.
- Exception safety
- Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
- Example
- The following code shows an example for the
object function.
2 #include <nlohmann/json.hpp>
14 std::cout << j_no_init_list << '\n';
15 std::cout << j_empty_init_list << '\n';
16 std::cout << j_list_of_pairs << '\n';
26 std::cout << e.what() << '\n';
static basic_json object(initializer_list_t init={}) explicitly create an object from an initializer list
detail::type_error type_error exception indicating executing a member function with a wrong type
basic_json<> json default JSON class
Output (play with this example online): {}
{}
{"one":1,"two":2}
[json.exception.type_error.301] cannot create object from initializer list
The example code above can be translated withg++ -std=c++11 -Isingle_include doc/examples/object.cpp -o object
- See also
- see basic_json(initializer_list_t, bool, value_t) – create a JSON value from an initializer list
-
see array(initializer_list_t) – create a JSON array value from an initializer list
- Since
- version 1.0.0
Definition at line 19328 of file json.hpp.
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