Niels Lohmann
8a0679558f
- Copying is disabled because of its cost, not because of two documents borrowing the same buffer; the unique_ptr follows from move-only. - Inputs: streams, FILE*, and wide characters (strings, arrays, pointers) are all supported and owned; point to parse_copy() for owned copies. - The error replay only runs for failing input, builds no values, and is skipped with allow_exceptions = false. - read() writes copied inputs into the previous owned copy. - Views can dangle like std::string_view, and why there is no shared/weak pointer design. - The 4 GiB limit (16-byte nodes, 16-byte scanner steps), streams being read to the end first, which macros apply, why materialize() has no source positions, and wording nits (accept() vs basic_json::accept(), is_binary, is_discarded, see-also lists, size table, "back into"). Signed-off-by: Niels Lohmann <mail@nlohmann.me>
1.0 KiB
1.0 KiB
nlohmann::basic_json_view::is_object
bool is_object() const noexcept;
This function returns #!cpp true if and only if the value is an object.
Return value
#!cpp true if the type is an object, #!cpp false otherwise.
Exception safety
No-throw guarantee: this function never throws exceptions.
Complexity
Constant.
Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
See also
- is_structured - return whether the type is structured
- size - the number of elements
- empty - whether there are no elements
BasicJsonType::is_object- the corresponding function ofbasic_json
Version history
- Added in version 3.13.0.