json/include/nlohmann/detail/meta
Florian Albrechtskirchinger 5352856f04
Implement support for string_view (attempt no. 3) (#3423)
* Add key_compare member to ordered_map

* Replace == with key_compare in ordered_map

* Expose the actual comparison function used by object_t

nlohmann::ordered_map uses a different comparison function than the one
provided via template parameter.
* Introduce a type trait to detect if object_t has a key_compare member.
* Rename object_comparator_t to default_object_comparator_t.
* Add object_comparator_t to be conditionally defined as
  object_t::key_compare, if available, or default_object_comparator_t
  otherwise.
* Update the documentation accordingly.

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

* Add type traits to check if a type is usable as object key

Add type trait to check:
* if a type is a specialization of a template.
* if a type is a json_pointer.
* if a type is a basic_json::{const_,}iterator.
* if two types are comparable using a given comparison functor.
* if a type is comparable to basic_json::object_t::key_type.
* if a type has a member type is_transparent.
* if a type is usable as object key.
* if a type has an erase() function accepting a given KeyType.

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

* Rework basic_json element access to accept more key types

Rework basic_json element access member functions and operators to
accept any type that meets the requirements defined by type trait
detail::is_usable_as_key_type.

Member functions and operators:
* at()
* operator[]
* value()
* erase()
* find()
* count()
* contains()

Update documentation to reflect these changes.

Add unit tests to excercise the new functions using std::string_view.

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>
2022-04-29 21:40:02 +02:00
..
call_std meta: fix is_compatible/constructible traits (#3020) 2021-10-07 12:32:25 +02:00
cpp_future.hpp Improve unit testing (Part 1) (#3380) 2022-03-24 07:54:07 +01:00
detected.hpp Properly constrain the basic_json conversion operator 2021-07-19 11:16:27 -04:00
identity_tag.hpp Reduced code duplication, renamed tag to identity_tag. 2021-01-10 19:23:32 +01:00
is_sax.hpp 🚸 add static assertion for missing binary function in SAX interface 2020-07-17 20:41:11 +02:00
type_traits.hpp Implement support for string_view (attempt no. 3) (#3423) 2022-04-29 21:40:02 +02:00
void_t.hpp 🎨 replace alternative operators (and, not, or) 2020-06-03 14:20:36 +02:00