mirror of
https://github.com/nlohmann/json.git
synced 2026-07-09 12:05:10 +00:00
deploy: 7c9208bfb3
This commit is contained in:
File diff suppressed because one or more lines are too long
@@ -0,0 +1,73 @@
|
||||
# nlohmann::basic_json::array_t
|
||||
|
||||
```
|
||||
using array_t = ArrayType<basic_json, AllocatorType<basic_json>>;
|
||||
```
|
||||
|
||||
The type used to store JSON arrays.
|
||||
|
||||
[RFC 8259](https://tools.ietf.org/html/rfc8259) describes JSON arrays as follows:
|
||||
|
||||
> An array is an ordered sequence of zero or more values.
|
||||
|
||||
To store objects in C++, a type is defined by the template parameters explained below.
|
||||
|
||||
## Template parameters
|
||||
|
||||
`ArrayType` : container type to store arrays (e.g., `std::vector` or `std::list`)
|
||||
|
||||
`AllocatorType` : the allocator to use for objects (e.g., `std::allocator`)
|
||||
|
||||
## Notes
|
||||
|
||||
#### Default type
|
||||
|
||||
With the default values for `ArrayType` (`std::vector`) and `AllocatorType` (`std::allocator`), the default value for `array_t` is:
|
||||
|
||||
```
|
||||
std::vector<
|
||||
basic_json, // value_type
|
||||
std::allocator<basic_json> // allocator_type
|
||||
>
|
||||
```
|
||||
|
||||
#### Limits
|
||||
|
||||
[RFC 8259](https://tools.ietf.org/html/rfc8259) specifies:
|
||||
|
||||
> An implementation may set limits on the maximum depth of nesting.
|
||||
|
||||
In this class, the array's limit of nesting is not explicitly constrained. However, a maximum depth of nesting may be introduced by the compiler or runtime environment. A theoretical limit can be queried by calling the [`max_size`](https://json.nlohmann.me/api/basic_json/max_size/index.md) function of a JSON array.
|
||||
|
||||
#### Storage
|
||||
|
||||
Arrays are stored as pointers in a `basic_json` type. That is, for any access to array values, a pointer of type `array_t*` must be dereferenced.
|
||||
|
||||
## Examples
|
||||
|
||||
Example
|
||||
|
||||
The following code shows that `array_t` is by default, a typedef to `std::vector<nlohmann::json>`.
|
||||
|
||||
```
|
||||
#include <iostream>
|
||||
#include <iomanip>
|
||||
#include <nlohmann/json.hpp>
|
||||
|
||||
using json = nlohmann::json;
|
||||
|
||||
int main()
|
||||
{
|
||||
std::cout << std::boolalpha << std::is_same<std::vector<json>, json::array_t>::value << std::endl;
|
||||
}
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
```
|
||||
true
|
||||
```
|
||||
|
||||
## Version history
|
||||
|
||||
- Added in version 1.0.0.
|
||||
Reference in New Issue
Block a user