// (1) iterator erase(iterator pos); const_iterator erase(const_iterator pos); // (2) iterator erase(iterator first, iterator last); const_iterator erase(const_iterator first, const_iterator last); // (3) size_type erase(const typename object_t::key_type& key); // (4) template<typename KeyType> size_type erase(KeyType&& key); // (5) void erase(const size_type idx);
Removes an element from a JSON value specified by iterator pos
. The iterator pos
must be valid and dereferenceable. Thus, the end()
iterator (which is valid, but is not dereferenceable) cannot be used as a value for pos
.
If called on a primitive type other than #!json null
, the resulting JSON value will be #!json null
.
Remove an element range specified by [first; last)
from a JSON value. The iterator first
does not need to be dereferenceable if first == last
: erasing an empty range is a no-op.
If called on a primitive type other than #!json null
, the resulting JSON value will be #!json null
.
Removes an element from a JSON object by key.
See 3. This overload is only available if KeyType
is comparable with #!cpp typename object_t::key_type
and #!cpp typename object_comparator_t::is_transparent
denotes a type.
Removes an element from a JSON array by index.
KeyType
: A type for an object key other than json_pointer
that is comparable with string_t
using object_comparator_t
. This can also be a string view (C++17).
pos
(in) : iterator to the element to remove
first
(in) : iterator to the beginning of the range to remove
last
(in) : iterator past the end of the range to remove
key
(in) : object key of the elements to remove
idx
(in) : array index of the element to remove
pos
refers to the last element, the end()
iterator is returned.last
refers to the last element, the end()
iterator is returned.ObjectType
is the default std::map
type, the return value will always be 0
(key
was not found) or 1
(key
was found).Strong exception safety: if an exception occurs, the original value stays intact.
type_error.307
if called on a null
value; example: "cannot use erase() with null"
invalid_iterator.202
if called on an iterator which does not belong to the current JSON value; example: "iterator does not fit current value"
invalid_iterator.205
if called on a primitive type with invalid iterator (i.e., any iterator which is not begin()
); example: "iterator out of range"
type_error.307
if called on a null
value; example: "cannot use erase() with null"
invalid_iterator.203
if called on iterators which does not belong to the current JSON value; example: "iterators do not fit current value"
invalid_iterator.204
if called on a primitive type with invalid iterators (i.e., if first != begin()
and last != end()
); example: "iterators out of range"
type_error.307
when called on a type other than JSON object; example: "cannot use erase() with null"
type_error.307
when called on a type other than JSON object; example: "cannot use erase() with null"
out_of_range.401
when idx >= size()
; example: "array index 17 is out of range"
pos
and the end of the container - strings and binary: linear in the length of the member - other types: constantlog(size()) + std::distance(first, last)
- arrays: linear in the distance between first
and last
, plus linear in the distance between last
and end of the container - strings and binary: linear in the length of the member - other types: constantlog(size()) + count(key)
log(size()) + count(key)
idx
and the end of the container.erase
, including the end()
iterator.??? example “Example: (1) remove element given an iterator”
The example shows the effect of `erase()` for different JSON types using an iterator. ```cpp --8<-- "examples/erase__IteratorType.cpp" ``` Output: ```json --8<-- "examples/erase__IteratorType.output" ```
??? example “Example: (2) remove elements given an iterator range”
The example shows the effect of `erase()` for different JSON types using an iterator range. ```cpp --8<-- "examples/erase__IteratorType_IteratorType.cpp" ``` Output: ```json --8<-- "examples/erase__IteratorType_IteratorType.output" ```
??? example “Example: (3) remove element from a JSON object given a key”
The example shows the effect of `erase()` for different JSON types using an object key. ```cpp --8<-- "examples/erase__object_t_key_type.cpp" ``` Output: ```json --8<-- "examples/erase__object_t_key_type.output" ```
??? example “Example: (4) remove element from a JSON object given a key using string_view”
The example shows the effect of `erase()` for different JSON types using an object key. ```cpp --8<-- "examples/erase__keytype.c++17.cpp" ``` Output: ```json --8<-- "examples/erase__keytype.c++17.output" ```
??? example “Example: (5) remove element from a JSON array given an index”
The example shows the effect of `erase()` using an array index. ```cpp --8<-- "examples/erase__size_type.cpp" ``` Output: ```json --8<-- "examples/erase__size_type.output" ```