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Add ONLY_SERIALIZE for NLOHMANN_DEFINE_DERIVED_TYPE_* macros (#4562)

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Einars Netlis-Galejs
2024-12-20 10:31:22 +00:00
committed by GitHub
parent 58f5f25968
commit af4ad7915c
6 changed files with 96 additions and 11 deletions
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43
docs/mkdocs/docs/api/macros/nlohmann_define_derived_type.md
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@ -1,20 +1,23 @@
<h1>NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE, NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT,
NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE, NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT</h1>
NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE, NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE,
NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT, NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE</h1>
```cpp
#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(type, base_type, member...) // (1)
#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(type, base_type, member...) // (2)
#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(type, base_type, member...) // (1)
#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(type, base_type, member...) // (2)
#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(type, base_type, member...) // (3)
#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(type, base_type, member...) // (3)
#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(type, base_type, member...) // (4)
#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(type, base_type, member...) // (4)
#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(type, base_type, member...) // (5)
#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(type, base_type, member...) // (6)
```
These macros can be used to simplify the serialization/deserialization of derived types if you want to use a JSON
object as serialization and want to use the member variable names as object keys in that object.
- Macros 1 and 2 are to be defined **inside** the class/struct to create code for.
- Macros 1, 2 and 3 are to be defined **inside** the class/struct to create code for.
Like [`NLOHMANN_DEFINE_TYPE_INTRUSIVE`](nlohmann_define_type_intrusive.md), they can access private members.
- Macros 3 and 4 are to be defined **outside** the class/struct to create code for, but **inside** its namespace.
- Macros 4, 5 and 6 are to be defined **outside** the class/struct to create code for, but **inside** its namespace.
Like [`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE`](nlohmann_define_type_non_intrusive.md),
they **cannot** access private members.
@ -48,14 +51,20 @@ friend void to_json(nlohmann::json&, const type&);
friend void from_json(const nlohmann::json&, type&);
```
Macros 3 and 4 add two functions to the namespace which take care of the serialization and deserialization:
Macros 4 and 5 add two functions to the namespace which take care of the serialization and deserialization:
```cpp
void to_json(nlohmann::json&, const type&);
void from_json(const nlohmann::json&, type&);
```
In both cases they call the `to_json`/`from_json` functions of the base type
Macros 3 and 6 add one function to the namespace which take care of the serialization only:
```cpp
void to_json(nlohmann::json&, const type&);
```
In first two cases cases they call the `to_json`/`from_json` functions of the base type
before serializing/deserializing the members of the derived type:
```cpp
@ -73,12 +82,24 @@ void from_json(const nlohmann::json& j, B& b) {
}
```
In the third case only `to_json` will be called:
```cpp
class A { /* ... */ };
class B : public A { /* ... */ };
void to_json(nlohmann::json& j, const B& b) {
nlohmann::to_json(j, static_cast<const A&>(b));
// ...
}
```
## Notes
!!! info "Prerequisites"
- Macros 1 and 2 have the same prerequisites of NLOHMANN_DEFINE_TYPE_INTRUSIVE.
- Macros 3 and 3 have the same prerequisites of NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE.
- Macros 1, 2 and 3 have the same prerequisites of NLOHMANN_DEFINE_TYPE_INTRUSIVE.
- Macros 4, 5 and 6 have the same prerequisites of NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE.
- Serialization/deserialization of base types must be defined.
!!! warning "Implementation limits"

2
docs/mkdocs/docs/features/macros.md
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@ -102,8 +102,10 @@ See [full documentation of `JSON_USE_IMPLICIT_CONVERSIONS`](../api/macros/json_u
## `NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(type, base_type, member...)`
## `NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(type, base_type, member...)`
## `NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(type, base_type, member...)`
## `NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(type, base_type, member...)`
## `NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(type, base_type, member...)`
## `NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(type, base_type, member...)`
## `NLOHMANN_DEFINE_TYPE_INTRUSIVE(type, member...)`

2
docs/mkdocs/mkdocs.yml
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@ -287,8 +287,10 @@ nav:
- 'JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON': api/macros/json_use_legacy_discarded_value_comparison.md
- 'NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE': api/macros/nlohmann_define_derived_type.md
- 'NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT': api/macros/nlohmann_define_derived_type.md
- 'NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE': api/macros/nlohmann_define_derived_type.md
- 'NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE': api/macros/nlohmann_define_derived_type.md
- 'NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT': api/macros/nlohmann_define_derived_type.md
- 'NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE': api/macros/nlohmann_define_derived_type.md
- 'NLOHMANN_DEFINE_TYPE_INTRUSIVE': api/macros/nlohmann_define_type_intrusive.md
- 'NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT': api/macros/nlohmann_define_type_intrusive.md
- 'NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE': api/macros/nlohmann_define_type_non_intrusive.md

6
include/nlohmann/detail/macro_scope.hpp
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@ -442,6 +442,9 @@
friend void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
friend void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }
#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(Type, BaseType, ...) \
friend void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
/*!
@brief macro
@def NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE
@ -455,6 +458,9 @@
inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
inline void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }
#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(Type, BaseType, ...) \
inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
// inspired from https://stackoverflow.com/a/26745591
// allows to call any std function as if (e.g. with begin):
// using std::begin; begin(x);

6
single_include/nlohmann/json.hpp
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@ -2809,6 +2809,9 @@ JSON_HEDLEY_DIAGNOSTIC_POP
friend void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
friend void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }
#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(Type, BaseType, ...) \
friend void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
/*!
@brief macro
@def NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE
@ -2822,6 +2825,9 @@ JSON_HEDLEY_DIAGNOSTIC_POP
inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
inline void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }
#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(Type, BaseType, ...) \
inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
// inspired from https://stackoverflow.com/a/26745591
// allows to call any std function as if (e.g. with begin):
// using std::begin; begin(x);

48
tests/src/unit-udt_macro.cpp
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@ -440,6 +440,32 @@ class person_without_default_constructor_2
NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(person_without_default_constructor_2, name, age)
class derived_person_only_serialize_public : public person_without_default_constructor_1
{
public:
std::string hair_color;
derived_person_only_serialize_public(std::string name_, int age_, std::string hair_color_)
: person_without_default_constructor_1(std::move(name_), age_)
, hair_color(std::move(hair_color_))
{}
};
NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(derived_person_only_serialize_public, person_without_default_constructor_1, hair_color)
class derived_person_only_serialize_private : person_without_default_constructor_1
{
private:
std::string hair_color;
public:
derived_person_only_serialize_private(std::string name_, int age_, std::string hair_color_)
: person_without_default_constructor_1(std::move(name_), age_)
, hair_color(std::move(hair_color_))
{}
NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(derived_person_only_serialize_private, person_without_default_constructor_1, hair_color)
};
} // namespace persons
TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRUSIVE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE", T, // NOLINT(readability-math-missing-parentheses)
@ -657,3 +683,25 @@ TEST_CASE_TEMPLATE("Serialization of non-default-constructible classes via NLOHM
}
}
}
TEST_CASE_TEMPLATE("Serialization of non-default-constructible classes via NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE and NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE", T, // NOLINT(readability-math-missing-parentheses)
persons::derived_person_only_serialize_public,
persons::derived_person_only_serialize_private)
{
SECTION("derived person only serialize")
{
{
// serialization of a single object
T person{"Erik", 1, "brown"};
CHECK(json(person).dump() == "{\"age\":1,\"hair_color\":\"brown\",\"name\":\"Erik\"}");
// serialization of a container with objects
std::vector<T> const two_persons
{
{"Erik", 1, "brown"},
{"Kyle", 2, "black"}
};
CHECK(json(two_persons).dump() == "[{\"age\":1,\"hair_color\":\"brown\",\"name\":\"Erik\"},{\"age\":2,\"hair_color\":\"black\",\"name\":\"Kyle\"}]");
}
}
}