basic_json unflatten() const;
The function restores the arbitrary nesting of a JSON value that has been flattened before using the flatten()
function. The JSON value must meet certain constraints:
the original JSON from a flattened version
The function can throw the following exceptions:
type_error.314
if value is not an objecttype_error.315
if object values are not primitiveStrong exception safety: if an exception occurs, the original value stays intact.
Linear in the size the JSON value.
Empty objects and arrays are flattened by flatten()
to #!json null
values and can not unflattened to their original type. Apart from this example, for a JSON value j
, the following is always true: #!cpp j == j.flatten().unflatten()
.
??? example
The following code shows how a flattened JSON object is unflattened into the original nested JSON object. ```cpp --8<-- "examples/unflatten.cpp" ``` Output: ```json --8<-- "examples/unflatten.output" ```