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Niels Lohmann
289d61ef4f
Conflicts: - include/nlohmann/json.hpp: took develop's removal of the UDLs (moved to json_literals.hpp, which already has the corrected @sa links) - single_include/nlohmann/json.hpp: regenerated with make amalgamate - docs/mkdocs/docs/api/operator_literal_json.md, operator_literal_json_pointer.md: kept the PR's migration guide link and develop's json_literals.hpp/JSON_NO_AUTOMATIC_UDLS note - docs/mkdocs/docs/api/basic_json/to_bson.md: both sides added out_of_range.415; kept develop's example message and both version history lines - docs/docset/docSet.sql: added JSON_NO_AUTOMATIC_UDLS (new on develop), which the PR's check_structure.py requires Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2.0 KiB
2.0 KiB
nlohmann::operator""_json
json operator ""_json(const char* s, std::size_t n);
json operator ""_json(const char8_t* s, std::size_t n); // since C++20
This operator implements a user-defined string literal for JSON objects. It can be used by adding #!cpp _json to a
string literal and returns a json object if no parse error occurred.
It is recommended to bring the operator into scope using any of the following lines:
using nlohmann::literals::operator ""_json;
using namespace nlohmann::literals;
using namespace nlohmann::json_literals;
using namespace nlohmann::literals::json_literals;
using namespace nlohmann;
This is suggested to ease migration to the next major version release of the library. See
JSON_USE_GLOBAL_UDLS and the
migration guide for details. The operator is
declared in header <nlohmann/json_literals.hpp>, which <nlohmann/json.hpp> includes unless
JSON_NO_AUTOMATIC_UDLS is defined.
Parameters
s(in)- a string representation of a JSON object
n(in)- length of string
s
Return value
json value parsed from s
Exceptions
The function can throw anything that parse(s, s+n) would throw.
Complexity
Linear.
Examples
??? example
The following code shows how to create JSON values from string literals.
```cpp
--8<-- "examples/operator_literal_json.cpp"
```
Output:
```json
--8<-- "examples/operator_literal_json.output"
```
See also
- Creating JSON values - the article on creating JSON values
- JSON_NO_AUTOMATIC_UDLS - do not include the user-defined string literals automatically
Version history
- Added in version 1.0.0.
- Moved to namespace
nlohmann::literals::json_literalsin 3.11.0. - Added
char8_t*overload in version 3.13.0.