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Niels Lohmann
526b6d3fd6
A review of all documentation pages found factual errors, dead links, missing cross-references, and gaps in examples. This fixes them and adds checks so the same problems are caught automatically. Fixes: - wrong signatures and version histories (operator!= C++20 member, binary() subtype type, get<PointerType>(), JSON_NO_THREAD_LOCAL, ...) - stale descriptions (number parsing since #5283, UBJSON table, SAX example that no longer compiled, tsl::ordered_map advice) - dead internal and external links; repology.org badges (the domain is suspended) replaced by badges that query the registries directly - deprecation notes link the migration guide; the guide itself fixed Additions: - "See also" sections, cross-references, 25 runnable examples, 12 Mermaid diagrams, new API pages for json_pointer::operator<=> and byte_container_with_subtype::operator==/!= - landing page, guides for untrusted input and performance - "unreleased" badge after versions newer than the latest release Checks: - strict documentation build (broken links/anchors fail it); CI and the publish workflow fetch the full history the build needs - weekly external link check, Mermaid syntax check in CI - check_structure.py: example titles, heading levels, alt texts, header links, docset index coverage; its unused-example check works again - all examples produce the same output on every platform Signed-off-by: Niels Lohmann <mail@nlohmann.me>
1.4 KiB
1.4 KiB
nlohmann::basic_json::boolean_t
using boolean_t = BooleanType;
The type used to store JSON booleans.
RFC 8259 implicitly describes a boolean as a type which differentiates the two
literals #!json true and #!json false.
To store boolean values in C++, a type is defined by the template parameter BooleanType which chooses the type to use.
Template parameters
BooleanType- the type to store booleans. As it is stored directly inside a
basic_jsonvalue (in a union), it must be a trivially default-constructible, trivially copyable, and trivially destructible type that is convertible to and from#!cpp bool. See Template Parameter Requirements.
Notes
Default type
With the default values for BooleanType (#!cpp bool), the default value for boolean_t is #!cpp bool.
Storage
Boolean values are stored directly inside a basic_json type.
Examples
??? example
The following code shows that `boolean_t` is by default, a typedef to `#!cpp bool`.
```cpp
--8<-- "examples/boolean_t.cpp"
```
Output:
```json
--8<-- "examples/boolean_t.output"
```
See also
- is_boolean checks whether the JSON value is a boolean
Version history
- Added in version 1.0.0.