Overwork documentation (#4516)

This commit is contained in:
Niels Lohmann
2024-12-09 23:02:30 +01:00
committed by GitHub
parent 9f60e85557
commit 549c79ba7e
68 changed files with 1085 additions and 335 deletions

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@@ -29,9 +29,9 @@ Unlike the [`parse`](parse.md) function, this function neither throws an excepti
: A compatible input, for instance:
- an `std::istream` object
- a `FILE` pointer (must not be null)
- a `FILE` pointer (throws if null)
- a C-style array of characters
- a pointer to a null-terminated string of single byte characters
- a pointer to a null-terminated string of single byte characters (throws if null)
- a `std::string`
- an object `obj` for which `begin(obj)` and `end(obj)` produces a valid pair of iterators.
@@ -64,18 +64,17 @@ Whether the input is valid JSON.
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
## Exceptions
Throws [`parse_error.101`](../../home/exceptions.md#jsonexceptionparse_error101) in case of an empty input like a null `FILE*` or `char*` pointer.
## Complexity
Linear in the length of the input. The parser is a predictive LL(1) parser.
## Notes
(1) A UTF-8 byte order mark is silently ignored.
!!! danger "Runtime assertion"
The precondition that a passed `#!cpp FILE` pointer must not be null is enforced with a
[runtime assertion](../../features/assertions.md).
A UTF-8 byte order mark is silently ignored.
## Examples
@@ -102,6 +101,7 @@ Linear in the length of the input. The parser is a predictive LL(1) parser.
- Added in version 3.0.0.
- Ignoring comments via `ignore_comments` added in version 3.9.0.
- Changed [runtime assertion](../../features/assertions.md) in case of `FILE*` null pointers to exception in version 3.11.4.
!!! warning "Deprecation"

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@@ -14,6 +14,11 @@ created from `args`.
`Args`
: compatible types to create a `basic_json` object
## Iterator invalidation
For [`ordered_json`](../ordered_json.md), adding a value to an object can yield a reallocation, in which case all
iterators (including the `end()` iterator) and all references to the elements are invalidated.
## Parameters
`args` (in)

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@@ -13,6 +13,12 @@ Creates a JSON value from the passed parameters `args` to the end of the JSON va
`Args`
: compatible types to create a `basic_json` object
## Iterator invalidation
By adding an element to the end of the array, a reallocation can happen, in which case all iterators (including the
[`end()`](end.md) iterator) and all references to the elements are invalidated. Otherwise, only the [`end()`](end.md)
iterator is invalidated.
## Parameters
`args` (in)
@@ -48,6 +54,11 @@ Amortized constant.
--8<-- "examples/emplace_back.output"
```
## See also
- [operator+=](operator+=.md) add a value to an array/object
- [push_back](push_back.md) add a value to an array/object
## Version history
- Since version 2.0.8.

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@@ -8,24 +8,36 @@ This class is an extension of [`std::exception`](https://en.cppreference.com/w/c
member `id` for exception ids. It is used as the base class for all exceptions thrown by the `basic_json` class. This
class can hence be used as "wildcard" to catch exceptions, see example below.
```plantuml
std::exception <|-- basic_json::exception
basic_json::exception <|-- basic_json::parse_error
basic_json::exception <|-- basic_json::invalid_iterator
basic_json::exception <|-- basic_json::type_error
basic_json::exception <|-- basic_json::out_of_range
basic_json::exception <|-- basic_json::other_error
```mermaid
classDiagram
direction LR
class std_exception ["std::exception"] {
<<interface>>
}
interface std::exception {}
class json_exception ["basic_json::exception"] {
+const int id
+const char* what() const
}
class json_parse_error ["basic_json::parse_error"] {
+const std::size_t byte
}
class basic_json::exception #FFFF00 {
+ const int id
+ const char* what() const
}
class json_invalid_iterator ["basic_json::invalid_iterator"]
class json_type_error ["basic_json::type_error"]
class json_out_of_range ["basic_json::out_of_range"]
class json_other_error ["basic_json::other_error"]
class basic_json::parse_error {
+ const std::size_t byte
}
std_exception <|-- json_exception
json_exception <|-- json_parse_error
json_exception <|-- json_invalid_iterator
json_exception <|-- json_type_error
json_exception <|-- json_out_of_range
json_exception <|-- json_other_error
style json_exception fill:#CCCCFF
```
Subclasses:

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@@ -37,7 +37,9 @@ Constant.
The pointer becomes invalid if the underlying JSON object changes.
Consider the following example code where the pointer `ptr` changes after the array is resized. As a result, reading or writing to `ptr` after the array change would be undefined behavior. The address of the first array element changes, because the underlying `std::vector` is resized after adding a fifth element.
Consider the following example code where the pointer `ptr` changes after the array is resized. As a result,
reading or writing to `ptr` after the array change would be undefined behavior. The address of the first array
element changes, because the underlying `std::vector` is resized after adding a fifth element.
```cpp
#include <iostream>

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@@ -42,7 +42,15 @@ class basic_json;
## Iterator invalidation
Todo
All operations that add values to an **array** ([`push_back`](push_back.md) , [`operator+=`](operator+=.md),
[`emplace_back`](emplace_back.md), [`insert`](insert.md), and [`operator[]`](operator%5B%5D.md) for a non-existing
index) can yield a reallocation, in which case all iterators (including the [`end()`](end.md) iterator) and all
references to the elements are invalidated.
For [`ordered_json`](../ordered_json.md), also all operations that add a value to an **object**
([`push_back`](push_back.md), [`operator+=`](operator+=.md), [`emplace`](emplace.md), [`insert`](insert.md),
[`update`](update.md), and [`operator[]`](operator%5B%5D.md) for a non-existing key) can yield a reallocation, in
which case all iterators (including the [`end()`](end.md) iterator) and all references to the elements are invalidated.
## Requirements

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@@ -24,6 +24,17 @@ void insert(const_iterator first, const_iterator last);
4. Inserts elements from initializer list `ilist` into array before iterator `pos`.
5. Inserts elements from range `[first, last)` into object.
## Iterator invalidation
For all cases where an element is added to an **array**, a reallocation can happen, in which case all iterators
(including the [`end()`](end.md) iterator) and all references to the elements are invalidated. Otherwise, only the
[`end()`](end.md) iterator is invalidated. Also, any iterator or reference after the insertion point will point to the
same index which is now a different value.
For [`ordered_json`](../ordered_json.md), also adding an element to an **object** can yield a reallocation which again
invalidates all iterators and all references. Also, any iterator or reference after the insertion point will point to
the same index which is now a different value.
## Parameters
`pos` (in)

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@@ -8,26 +8,36 @@ This exception is thrown if iterators passed to a library function do not match
Exceptions have ids 2xx (see [list of iterator errors](../../home/exceptions.md#iterator-errors)).
```plantuml
std::exception <|-- basic_json::exception
basic_json::exception <|-- basic_json::parse_error
basic_json::exception <|-- basic_json::invalid_iterator
basic_json::exception <|-- basic_json::type_error
basic_json::exception <|-- basic_json::out_of_range
basic_json::exception <|-- basic_json::other_error
```mermaid
classDiagram
direction LR
class std_exception ["std::exception"] {
<<interface>>
}
interface std::exception {}
class json_exception ["basic_json::exception"] {
+const int id
+const char* what() const
}
class json_parse_error ["basic_json::parse_error"] {
+const std::size_t byte
}
class basic_json::exception {
+ const int id
+ const char* what() const
}
class json_invalid_iterator ["basic_json::invalid_iterator"]
class json_type_error ["basic_json::type_error"]
class json_out_of_range ["basic_json::out_of_range"]
class json_other_error ["basic_json::other_error"]
class basic_json::parse_error {
+ const std::size_t byte
}
std_exception <|-- json_exception
json_exception <|-- json_parse_error
json_exception <|-- json_invalid_iterator
json_exception <|-- json_type_error
json_exception <|-- json_out_of_range
json_exception <|-- json_other_error
class basic_json::invalid_iterator #FFFF00 {}
style json_invalid_iterator fill:#CCCCFF
```
## Member functions

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@@ -66,7 +66,7 @@ When iterating over an array, `key()` will return the index of the element as st
!!! danger "Lifetime issues"
Using `items()` on temporary objects is dangerous. Make sure the object's lifetime exceeds the iteration. See
<https://github.com/nlohmann/json/issues/2040> for more information.
[#2040](https://github.com/nlohmann/json/issues/2040) for more information.
## Examples

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@@ -27,6 +27,15 @@ reference operator+=(initializer_list_t init);
`init` is converted into an object element and added using `operator+=(const typename object_t::value_type&)`.
Otherwise, `init` is converted to a JSON value and added using `operator+=(basic_json&&)`.
## Iterator invalidation
For all cases where an element is added to an **array**, a reallocation can happen, in which case all iterators (including
the [`end()`](end.md) iterator) and all references to the elements are invalidated. Otherwise, only the
[`end()`](end.md) iterator is invalidated.
For [`ordered_json`](../ordered_json.md), also adding an element to an **object** can yield a reallocation which again
invalidates all iterators and all references.
## Parameters
`val` (in)
@@ -103,6 +112,11 @@ interpreted as `object_t::value_type` or `std::initializer_list<basic_json>`, se
--8<-- "examples/push_back__initializer_list.output"
```
## See also
- [emplace_back](emplace_back.md) add a value to an array
- [push_back](push_back.md) add a value to an array/object
## Version history
1. Since version 1.0.0.

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@@ -34,6 +34,15 @@ const_reference operator[](const json_pointer& ptr) const;
[`string_t`](string_t.md) using [`object_comparator_t`](object_comparator_t.md).
This can also be a string view (C++17).
## Iterator invalidation
For the non-const versions 1. and 4., when passing an **array** index that does not exist, it is created and filled with
a `#!json null` value before a reference to it is returned. For this, a reallocation can happen, in which case all
iterators (including the [`end()`](end.md) iterator) and all references to the elements are invalidated.
For [`ordered_json`](../ordered_json.md), also passing an **object key** to the non-const versions 2., 3., and 4., a
reallocation can happen which again invalidates all iterators and all references.
## Parameters
`idx` (in)

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@@ -8,26 +8,36 @@ This exception is thrown in case of errors that cannot be classified with the ot
Exceptions have ids 5xx (see [list of other errors](../../home/exceptions.md#further-exceptions)).
```plantuml
std::exception <|-- basic_json::exception
basic_json::exception <|-- basic_json::parse_error
basic_json::exception <|-- basic_json::invalid_iterator
basic_json::exception <|-- basic_json::type_error
basic_json::exception <|-- basic_json::out_of_range
basic_json::exception <|-- basic_json::other_error
```mermaid
classDiagram
direction LR
class std_exception ["std::exception"] {
<<interface>>
}
interface std::exception {}
class json_exception ["basic_json::exception"] {
+const int id
+const char* what() const
}
class json_parse_error ["basic_json::parse_error"] {
+const std::size_t byte
}
class basic_json::exception {
+ const int id
+ const char* what() const
}
class json_invalid_iterator ["basic_json::invalid_iterator"]
class json_type_error ["basic_json::type_error"]
class json_out_of_range ["basic_json::out_of_range"]
class json_other_error ["basic_json::other_error"]
class basic_json::parse_error {
+ const std::size_t byte
}
std_exception <|-- json_exception
json_exception <|-- json_parse_error
json_exception <|-- json_invalid_iterator
json_exception <|-- json_type_error
json_exception <|-- json_out_of_range
json_exception <|-- json_other_error
class basic_json::other_error #FFFF00 {}
style json_other_error fill:#CCCCFF
```
## Member functions

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@@ -9,26 +9,36 @@ instance in case of array indices or nonexisting object keys.
Exceptions have ids 4xx (see [list of out-of-range errors](../../home/exceptions.md#out-of-range)).
```plantuml
std::exception <|-- basic_json::exception
basic_json::exception <|-- basic_json::parse_error
basic_json::exception <|-- basic_json::invalid_iterator
basic_json::exception <|-- basic_json::type_error
basic_json::exception <|-- basic_json::out_of_range
basic_json::exception <|-- basic_json::other_error
```mermaid
classDiagram
direction LR
class std_exception ["std::exception"] {
<<interface>>
}
interface std::exception {}
class json_exception ["basic_json::exception"] {
+const int id
+const char* what() const
}
class json_parse_error ["basic_json::parse_error"] {
+const std::size_t byte
}
class basic_json::exception {
+ const int id
+ const char* what() const
}
class json_invalid_iterator ["basic_json::invalid_iterator"]
class json_type_error ["basic_json::type_error"]
class json_out_of_range ["basic_json::out_of_range"]
class json_other_error ["basic_json::other_error"]
class basic_json::parse_error {
+ const std::size_t byte
}
std_exception <|-- json_exception
json_exception <|-- json_parse_error
json_exception <|-- json_invalid_iterator
json_exception <|-- json_type_error
json_exception <|-- json_out_of_range
json_exception <|-- json_other_error
class basic_json::out_of_range #FFFF00 {}
style json_out_of_range fill:#CCCCFF
```
## Member functions

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@@ -28,9 +28,9 @@ static basic_json parse(IteratorType first, IteratorType last,
: A compatible input, for instance:
- an `std::istream` object
- a `FILE` pointer (must not be null)
- a `FILE` pointer (throws if null)
- a C-style array of characters
- a pointer to a null-terminated string of single byte characters
- a pointer to a null-terminated string of single byte characters (throws if null)
- a `std::string`
- an object `obj` for which `begin(obj)` and `end(obj)` produces a valid pair of iterators.
@@ -73,10 +73,11 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
## Exceptions
- Throws [`parse_error.101`](../../home/exceptions.md#jsonexceptionparse_error101) in case of an unexpected token.
- Throws [`parse_error.102`](../../home/exceptions.md#jsonexceptionparse_error102) if to_unicode fails or surrogate
- Throws [`parse_error.101`](../../home/exceptions.md#jsonexceptionparse_error101) in case of an unexpected token, or
empty input like a null `FILE*` or `char*` pointer.
- Throws [`parse_error.102`](../../home/exceptions.md#jsonexceptionparse_error102) if `to_unicode` fails or surrogate
error.
- Throws [`parse_error.103`](../../home/exceptions.md#jsonexceptionparse_error103) if to_unicode fails.
- Throws [`parse_error.103`](../../home/exceptions.md#jsonexceptionparse_error103) if `to_unicode` fails.
## Complexity
@@ -86,12 +87,7 @@ super-linear complexity.
## Notes
(1) A UTF-8 byte order mark is silently ignored.
!!! danger "Runtime assertion"
The precondition that a passed `#!cpp FILE` pointer must not be null is enforced with a
[runtime assertion](../../features/assertions.md).
A UTF-8 byte order mark is silently ignored.
## Examples
@@ -203,6 +199,7 @@ super-linear complexity.
- Added in version 1.0.0.
- Overload for contiguous containers (1) added in version 2.0.3.
- Ignoring comments via `ignore_comments` added in version 3.9.0.
- Changed [runtime assertion](../../features/assertions.md) in case of `FILE*` null pointers to exception in version 3.11.4.
!!! warning "Deprecation"

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@@ -11,24 +11,36 @@ Member `byte` holds the byte index of the last read character in the input file
Exceptions have ids 1xx (see [list of parse errors](../../home/exceptions.md#parse-errors)).
```plantuml
std::exception <|-- basic_json::exception
basic_json::exception <|-- basic_json::parse_error
basic_json::exception <|-- basic_json::invalid_iterator
basic_json::exception <|-- basic_json::type_error
basic_json::exception <|-- basic_json::out_of_range
basic_json::exception <|-- basic_json::other_error
```mermaid
classDiagram
direction LR
class std_exception ["std::exception"] {
<<interface>>
}
interface std::exception {}
class json_exception ["basic_json::exception"] {
+const int id
+const char* what() const
}
class json_parse_error ["basic_json::parse_error"] {
+const std::size_t byte
}
class basic_json::exception {
+ const int id
+ const char* what() const
}
class json_invalid_iterator ["basic_json::invalid_iterator"]
class json_type_error ["basic_json::type_error"]
class json_out_of_range ["basic_json::out_of_range"]
class json_other_error ["basic_json::other_error"]
class basic_json::parse_error #FFFF00 {
+ const std::size_t byte
}
std_exception <|-- json_exception
json_exception <|-- json_parse_error
json_exception <|-- json_invalid_iterator
json_exception <|-- json_type_error
json_exception <|-- json_out_of_range
json_exception <|-- json_other_error
style json_parse_error fill:#CCCCFF
```
## Member functions

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@@ -27,6 +27,15 @@ void push_back(initializer_list_t init);
`init` is converted into an object element and added using `push_back(const typename object_t::value_type&)`.
Otherwise, `init` is converted to a JSON value and added using `push_back(basic_json&&)`.
## Iterator invalidation
For all cases where an element is added to an **array**, a reallocation can happen, in which case all iterators (including
the [`end()`](end.md) iterator) and all references to the elements are invalidated. Otherwise, only the
[`end()`](end.md) iterator is invalidated.
For [`ordered_json`](../ordered_json.md), also adding an element to an **object** can yield a reallocation which again
invalidates all iterators and all references.
## Parameters
`val` (in)
@@ -99,6 +108,11 @@ All functions can throw the following exception:
--8<-- "examples/push_back__initializer_list.output"
```
## See also
- [emplace_back](emplace_back.md) add a value to an array
- [operator+=](operator+=.md) add a value to an array/object
## Version history
1. Since version 1.0.0.

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@@ -9,26 +9,36 @@ does not match the expected semantics.
Exceptions have ids 3xx (see [list of type errors](../../home/exceptions.md#type-errors)).
```plantuml
std::exception <|-- basic_json::exception
basic_json::exception <|-- basic_json::parse_error
basic_json::exception <|-- basic_json::invalid_iterator
basic_json::exception <|-- basic_json::type_error
basic_json::exception <|-- basic_json::out_of_range
basic_json::exception <|-- basic_json::other_error
```mermaid
classDiagram
direction LR
class std_exception ["std::exception"] {
<<interface>>
}
interface std::exception {}
class json_exception ["basic_json::exception"] {
+const int id
+const char* what() const
}
class json_parse_error ["basic_json::parse_error"] {
+const std::size_t byte
}
class basic_json::exception {
+ const int id
+ const char* what() const
}
class json_invalid_iterator ["basic_json::invalid_iterator"]
class json_type_error ["basic_json::type_error"]
class json_out_of_range ["basic_json::out_of_range"]
class json_other_error ["basic_json::other_error"]
class basic_json::parse_error {
+ const std::size_t byte
}
std_exception <|-- json_exception
json_exception <|-- json_parse_error
json_exception <|-- json_invalid_iterator
json_exception <|-- json_type_error
json_exception <|-- json_out_of_range
json_exception <|-- json_other_error
class basic_json::type_error #FFFF00 {}
style json_type_error fill:#CCCCFF
```
## Member functions

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@@ -17,6 +17,11 @@ recursively merges objects with common keys.
The function is motivated by Python's [dict.update](https://docs.python.org/3.6/library/stdtypes.html#dict.update)
function.
## Iterator invalidation
For [`ordered_json`](../ordered_json.md), adding a value to an object can yield a reallocation, in which case all
iterators (including the `end()` iterator) and all references to the elements are invalidated.
## Parameters
`j` (in)