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Generate template functions with NLOHMANN_DEFINE_TYPE macros (#4597)

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* Support any basic_json type in NLOHMANN_DEFINE_TYPE_* macros

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Test NLOHMANN_DEFINE_TYPE_* macros also support unordered_json

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Simplify test about NLOHMANN_DEFINE_TYPE_ with many arguments

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Remove extra scope in macros tests

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Remove unused test class in macros tests

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Update documentation about NLOHMANN_DEFINE_TYPE_* macros

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Fix NLOHMANN_JSON_SERIALIZE_ENUM documentation

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Mark some variables const in macros tests, fixes clang-tidy

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Workaround clang 3.5 issue with const object initialization

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Update highlighted lines in NLOHMANN_DEFINE_TYPE_* macros examples

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Fix swapped macros in documentation

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Remove extra backslashes at the end of macros

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Require basic_json type in NLOHMANN_DEFINE_TYPE_* generated functions

Signed-off-by: kimci86 <kimci86@hotmail.fr>

* Fix typos in macros documentation

Signed-off-by: kimci86 <kimci86@hotmail.fr>

---------

Signed-off-by: kimci86 <kimci86@hotmail.fr>
This commit is contained in:
kimci86
2025-01-18 22:59:09 +01:00
committed by GitHub
parent bdb8d2b7b3
commit 8a882f32ed
14 changed files with 275 additions and 231 deletions
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24
docs/mkdocs/docs/api/macros/nlohmann_define_derived_type.md
View File

@@ -64,21 +64,26 @@ Summary:
Macros 1 and 2 add two friend functions to the class which take care of the serialization and deserialization:
```cpp
friend void to_json(nlohmann::json&, const type&);
friend void from_json(const nlohmann::json&, type&);
template<typename BasicJsonType>
friend void to_json(BasicJsonType&, const type&);
template<typename BasicJsonType>
friend void from_json(const BasicJsonType&, type&);
```
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&);
template<typename BasicJsonType>
void to_json(BasicJsonType&, const type&);
template<typename BasicJsonType>
void from_json(const BasicJsonType&, 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&);
template<typename BasicJsonType>
void to_json(BasicJsonType&, const type&);
```
In first two cases, they call the `to_json`/`from_json` functions of the base type
@@ -88,12 +93,14 @@ before serializing/deserializing the members of the derived type:
class A { /* ... */ };
class B : public A { /* ... */ };
void to_json(nlohmann::json& j, const B& b) {
template<typename BasicJsonType>
void to_json(BasicJsonType& j, const B& b) {
nlohmann::to_json(j, static_cast<const A&>(b));
// ...
}
void from_json(const nlohmann::json& j, B& b) {
template<typename BasicJsonType>
void from_json(const BasicJsonType& j, B& b) {
nlohmann::from_json(j, static_cast<A&>(b));
// ...
}
@@ -105,7 +112,8 @@ In the third case, only `to_json` will be called:
class A { /* ... */ };
class B : public A { /* ... */ };
void to_json(nlohmann::json& j, const B& b) {
template<typename BasicJsonType>
void to_json(BasicJsonType& j, const B& b) {
nlohmann::to_json(j, static_cast<const A&>(b));
// ...
}

14
docs/mkdocs/docs/api/macros/nlohmann_define_type_intrusive.md
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@@ -40,8 +40,10 @@ Summary:
The macros add two friend functions to the class which take care of the serialization and deserialization:
```cpp
friend void to_json(nlohmann::json&, const type&);
friend void from_json(const nlohmann::json&, type&); // except (3)
template<typename BasicJsonType>
friend void to_json(BasicJsonType&, const type&);
template<typename BasicJsonType>
friend void from_json(const BasicJsonType&, type&); // except (3)
```
See examples below for the concrete generated code.
@@ -60,8 +62,6 @@ See examples below for the concrete generated code.
- The current implementation is limited to at most 64 member variables. If you want to serialize/deserialize types
with more than 64 member variables, you need to define the `to_json`/`from_json` functions manually.
- The macros only work for the [`nlohmann::json`](../json.md) type; other specializations such as
[`nlohmann::ordered_json`](../ordered_json.md) are currently unsupported.
## Examples
@@ -90,7 +90,7 @@ See examples below for the concrete generated code.
The macro is equivalent to:
```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34"
```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34 35 36"
--8<-- "examples/nlohmann_define_type_intrusive_explicit.cpp"
```
@@ -118,7 +118,7 @@ See examples below for the concrete generated code.
The macro is equivalent to:
```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34 35"
```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37"
--8<-- "examples/nlohmann_define_type_intrusive_with_default_explicit.cpp"
```
@@ -147,7 +147,7 @@ See examples below for the concrete generated code.
The macro is equivalent to:
```cpp hl_lines="22 22 23 24 25 26 27"
```cpp hl_lines="22 22 23 24 25 26 27 28"
--8<-- "examples/nlohmann_define_type_intrusive_only_serialize_explicit.cpp"
```

16
docs/mkdocs/docs/api/macros/nlohmann_define_type_non_intrusive.md
View File

@@ -40,8 +40,10 @@ Summary:
The macros 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&); // except (3)
template<typename BasicJsonType>
void to_json(BasicJsonType&, const type&);
template<typename BasicJsonType>
void from_json(const BasicJsonType&, type&); // except (3)
```
See examples below for the concrete generated code.
@@ -61,8 +63,6 @@ See examples below for the concrete generated code.
- The current implementation is limited to at most 64 member variables. If you want to serialize/deserialize types
with more than 64 member variables, you need to define the `to_json`/`from_json` functions manually.
- The macros only work for the [`nlohmann::json`](../json.md) type; other specializations such as
[`nlohmann::ordered_json`](../ordered_json.md) are currently unsupported.
## Examples
@@ -90,7 +90,7 @@ See examples below for the concrete generated code.
The macro is equivalent to:
```cpp hl_lines="16 17 18 19 20 21 22 23 24 25 26 27 28"
```cpp hl_lines="16 17 18 19 20 21 22 23 24 25 26 27 28 29 30"
--8<-- "examples/nlohmann_define_type_non_intrusive_explicit.cpp"
```
@@ -98,7 +98,7 @@ See examples below for the concrete generated code.
Consider the following complete example:
```cpp hl_lines="22"
```cpp hl_lines="21"
--8<-- "examples/nlohmann_define_type_non_intrusive_with_default_macro.cpp"
```
@@ -119,7 +119,7 @@ See examples below for the concrete generated code.
The macro is equivalent to:
```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34 35"
```cpp hl_lines="21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36"
--8<-- "examples/nlohmann_define_type_non_intrusive_with_default_explicit.cpp"
```
@@ -148,7 +148,7 @@ See examples below for the concrete generated code.
The macro is equivalent to:
```cpp hl_lines="16 17 18 19 20 21"
```cpp hl_lines="16 17 18 19 20 21 22"
--8<-- "examples/nlohmann_define_type_non_intrusive_only_serialize_explicit.cpp"
```

2
docs/mkdocs/docs/api/macros/nlohmann_json_serialize_enum.md
View File

@@ -20,7 +20,7 @@ The `NLOHMANN_JSON_SERIALIZE_ENUM` allows to define a user-defined serialization
## Default definition
The macros add two friend functions to the class which take care of the serialization and deserialization:
The macro adds two functions to the namespace which take care of the serialization and deserialization:
```cpp
template<typename BasicJsonType>

6
docs/mkdocs/docs/examples/nlohmann_define_type_intrusive_explicit.cpp
View File

@@ -19,14 +19,16 @@ class person
: name(std::move(name_)), address(std::move(address_)), age(age_)
{}
friend void to_json(nlohmann::json& nlohmann_json_j, const person& nlohmann_json_t)
template<typename BasicJsonType>
friend void to_json(BasicJsonType& nlohmann_json_j, const person& nlohmann_json_t)
{
nlohmann_json_j["name"] = nlohmann_json_t.name;
nlohmann_json_j["address"] = nlohmann_json_t.address;
nlohmann_json_j["age"] = nlohmann_json_t.age;
}
friend void from_json(const nlohmann::json& nlohmann_json_j, person& nlohmann_json_t)
template<typename BasicJsonType>
friend void from_json(const BasicJsonType& nlohmann_json_j, person& nlohmann_json_t)
{
nlohmann_json_t.name = nlohmann_json_j.at("name");
nlohmann_json_t.address = nlohmann_json_j.at("address");

3
docs/mkdocs/docs/examples/nlohmann_define_type_intrusive_only_serialize_explicit.cpp
View File

@@ -19,7 +19,8 @@ class person
: name(std::move(name_)), address(std::move(address_)), age(age_)
{}
friend void to_json(nlohmann::json& nlohmann_json_j, const person& nlohmann_json_t)
template<typename BasicJsonType>
friend void to_json(BasicJsonType& nlohmann_json_j, const person& nlohmann_json_t)
{
nlohmann_json_j["name"] = nlohmann_json_t.name;
nlohmann_json_j["address"] = nlohmann_json_t.address;

6
docs/mkdocs/docs/examples/nlohmann_define_type_intrusive_with_default_explicit.cpp
View File

@@ -19,14 +19,16 @@ class person
: name(std::move(name_)), address(std::move(address_)), age(age_)
{}
friend void to_json(nlohmann::json& nlohmann_json_j, const person& nlohmann_json_t)
template<typename BasicJsonType>
friend void to_json(BasicJsonType& nlohmann_json_j, const person& nlohmann_json_t)
{
nlohmann_json_j["name"] = nlohmann_json_t.name;
nlohmann_json_j["address"] = nlohmann_json_t.address;
nlohmann_json_j["age"] = nlohmann_json_t.age;
}
friend void from_json(const nlohmann::json& nlohmann_json_j, person& nlohmann_json_t)
template<typename BasicJsonType>
friend void from_json(const BasicJsonType& nlohmann_json_j, person& nlohmann_json_t)
{
person nlohmann_json_default_obj;
nlohmann_json_t.name = nlohmann_json_j.value("name", nlohmann_json_default_obj.name);

6
docs/mkdocs/docs/examples/nlohmann_define_type_non_intrusive_explicit.cpp
View File

@@ -13,14 +13,16 @@ struct person
int age;
};
void to_json(nlohmann::json& nlohmann_json_j, const person& nlohmann_json_t)
template<typename BasicJsonType>
void to_json(BasicJsonType& nlohmann_json_j, const person& nlohmann_json_t)
{
nlohmann_json_j["name"] = nlohmann_json_t.name;
nlohmann_json_j["address"] = nlohmann_json_t.address;
nlohmann_json_j["age"] = nlohmann_json_t.age;
}
void from_json(const nlohmann::json& nlohmann_json_j, person& nlohmann_json_t)
template<typename BasicJsonType>
void from_json(const BasicJsonType& nlohmann_json_j, person& nlohmann_json_t)
{
nlohmann_json_t.name = nlohmann_json_j.at("name");
nlohmann_json_t.address = nlohmann_json_j.at("address");

3
docs/mkdocs/docs/examples/nlohmann_define_type_non_intrusive_only_serialize_explicit.cpp
View File

@@ -13,7 +13,8 @@ struct person
int age;
};
void to_json(nlohmann::json& nlohmann_json_j, const person& nlohmann_json_t)
template<typename BasicJsonType>
void to_json(BasicJsonType& nlohmann_json_j, const person& nlohmann_json_t)
{
nlohmann_json_j["name"] = nlohmann_json_t.name;
nlohmann_json_j["address"] = nlohmann_json_t.address;

6
docs/mkdocs/docs/examples/nlohmann_define_type_non_intrusive_with_default_explicit.cpp
View File

@@ -18,14 +18,16 @@ struct person
{}
};
void to_json(nlohmann::json& nlohmann_json_j, const person& nlohmann_json_t)
template<typename BasicJsonType>
void to_json(BasicJsonType& nlohmann_json_j, const person& nlohmann_json_t)
{
nlohmann_json_j["name"] = nlohmann_json_t.name;
nlohmann_json_j["address"] = nlohmann_json_t.address;
nlohmann_json_j["age"] = nlohmann_json_t.age;
}
void from_json(const nlohmann::json& nlohmann_json_j, person& nlohmann_json_t)
template<typename BasicJsonType>
void from_json(const BasicJsonType& nlohmann_json_j, person& nlohmann_json_t)
{
person nlohmann_json_default_obj;
nlohmann_json_t.name = nlohmann_json_j.value("name", nlohmann_json_default_obj.name);

6
docs/mkdocs/docs/features/arbitrary_types.md
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@@ -89,10 +89,10 @@ There are six macros to make your life easier as long as you (1) want to use a J
- [`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(name, member1, member2, ...)`](../api/macros/nlohmann_define_type_non_intrusive.md) is to be defined inside the namespace of the class/struct to create code for. It will throw an exception in `from_json()` due to a missing value in the JSON object.
- [`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(name, member1, member2, ...)`](../api/macros/nlohmann_define_type_non_intrusive.md) is to be defined inside the namespace of the class/struct to create code for. It will not throw an exception in `from_json()` due to a missing value in the JSON object, but fills in values from object which is default-constructed by the type.
- [`NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE(name, member1, member2, ...)`](../api/macros/nlohmann_define_type_non_intrusive.md) is to be defined inside the namespace of the class/struct to create code for. It does not define a `fron_json()` function which is needed in case the type does not have a default constructor.
- [`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(name, member1, member2, ...)`](../api/macros/nlohmann_define_type_non_intrusive.md) is to be defined inside the namespace of the class/struct to create code for. It does not define a `from_json()` function which is needed in case the type does not have a default constructor.
- [`NLOHMANN_DEFINE_TYPE_INTRUSIVE(name, member1, member2, ...)`](../api/macros/nlohmann_define_type_intrusive.md) is to be defined inside the class/struct to create code for. This macro can also access private members. It will throw an exception in `from_json()` due to a missing value in the JSON object.
- [`NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT(name, member1, member2, ...)`](../api/macros/nlohmann_define_type_intrusive.md) is to be defined inside the class/struct to create code for. This macro can also access private members. It will not throw an exception in `from_json()` due to a missing value in the JSON object, but fills in values from object which is default-constructed by the type.
- [`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(name, member1, member2, ...)`](../api/macros/nlohmann_define_type_intrusive.md) is to be defined inside the class/struct to create code for. This macro can also access private members. It does not define a `fron_json()` function which is needed in case the type does not have a default constructor.
- [`NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE(name, member1, member2, ...)`](../api/macros/nlohmann_define_type_intrusive.md) is to be defined inside the class/struct to create code for. This macro can also access private members. It does not define a `from_json()` function which is needed in case the type does not have a default constructor.
Furthermore, there exist versions to use in case of derived classes:
@@ -120,8 +120,6 @@ For _derived_ classes and structs, use the following macros
- The current macro implementations are limited to at most 64 member variables. If you want to serialize/deserialize
types with more than 64 member variables, you need to define the `to_json`/`from_json` functions manually.
- The macros only work for the [`nlohmann::json`](../api/json.md) type; other specializations such as
[`nlohmann::ordered_json`](../api/ordered_json.md) are currently unsupported.
??? example