mirror of https://github.com/nlohmann/json.git synced 2026-09-30 22:15:19 +00:00

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Niels Lohmann 54455afa40 Document json_document and json_view

- API pages for basic_json_document and basic_json_view, one per member,
  and for the four aliases, each with an example
- features/json_view.md: the problem the view solves, ownership and
  lifetime, what matches basic_json::parse() and what differs, and when
  to choose json, ordered_json, SAX, or the view
- the examples show why one would use the view, not only how: borrowed
  vs. owned input, reading a few fields and materializing one subtree,
  reusing a document across many messages
- registered in the mkdocs navigation, llms.txt, the docset, the
  exceptions page (out_of_range.416), architecture.md, the integration
  page, and the README; the yyjson credit is added to the README and
  license.md

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

2026-09-29 14:02:43 +02:00

1.8 KiB

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nlohmann::basic_json_document::accept

template<typename InputType>
static bool accept(InputType&& input,
                   const bool ignore_comments = false,
                   const bool ignore_trailing_commas = false);

Checks whether the input is valid JSON, accepting and rejecting exactly what BasicJsonType::accept() does, with the same options. Unlike parse(), this function never throws an exception for invalid input, and the returned #!cpp bool is the only result -- no document is returned.

Template parameters

InputType: A compatible input; see parse.

Parameters

input (in): Input to check.
ignore_comments (in): whether comments should be ignored and treated like whitespace (#!cpp true) or yield a parse error (#!cpp false); (optional, #!cpp false by default)
ignore_trailing_commas (in): whether trailing commas in arrays or objects should be ignored and treated like whitespace (#!cpp true) or yield a parse error (#!cpp false); (optional, #!cpp false by default)

Return value

Whether the input is valid JSON.

Exception safety

Strong guarantee: this function itself never throws for an invalid input; it can only throw what allocating the input's own copy (for inputs that are always read into a buffer) throws.

Complexity

Linear in the length of the input.

Examples

??? example

```cpp
--8<-- "examples/basic_json_document__accept.cpp"
```

Output:

```json
--8<-- "examples/basic_json_document__accept.output"
```

Version history

Added in version 3.13.0.

1.8 KiB Raw Blame History