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79 lines
2.1 KiB
Markdown
79 lines
2.1 KiB
Markdown
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# basic_json::update
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```cpp
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// (1)
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void update(const_reference j);
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// (2)
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void update(const_iterator first, const_iterator last);
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```
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1. Inserts all values from JSON object `j` and overwrites existing keys.
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2. Inserts all values from from range `[first, last)` and overwrites existing keys.
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The function is motivated by Python's [dict.update](https://docs.python.org/3.6/library/stdtypes.html#dict.update)
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function.
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## Parameters
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`j` (in)
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: JSON object to read values from
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`first` (in)
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: begin of the range of elements to insert
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`last` (in)
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: end of the range of elements to insert
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## Exceptions
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1. The function can throw the following exceptions:
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- Throws [`type_error.312`](../../home/exceptions.md#jsonexceptiontype_error312) if called on JSON values other than
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objects; example: `"cannot use update() with string"`
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2. The function can throw thw following exceptions:
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- Throws [`type_error.312`](../../home/exceptions.md#jsonexceptiontype_error312) if called on JSON values other than
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objects; example: `"cannot use update() with string"`
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- Throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) if called on an
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iterator which does not belong to the current JSON value; example: `"iterator does not fit current value"`
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- Throws [`invalid_iterator.210`](../../home/exceptions.md#jsonexceptioninvalid_iterator210) if `first` and `last`
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do not belong to the same JSON value; example: `"iterators do not fit"`
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## Complexity
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1. O(N*log(size() + N)), where N is the number of elements to insert.
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2. O(N*log(size() + N)), where N is the number of elements to insert.
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## Example
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??? example
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The example shows how `update()` is used.
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```cpp
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--8<-- "examples/update.cpp"
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```
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Output:
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```json
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--8<-- "examples/update.output"
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```
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??? example
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The example shows how `update()` is used.
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```cpp
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--8<-- "examples/update__range.cpp"
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```
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Output:
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```json
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--8<-- "examples/update__range.output"
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```
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## Version history
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- Added in version 3.0.0.
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