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Generate template functions with NLOHMANN_DEFINE_TYPE macros (#4597)
* 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:
@@ -64,21 +64,26 @@ Summary:
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Macros 1 and 2 add two friend functions to the class which take care of the serialization and deserialization:
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```cpp
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friend void to_json(nlohmann::json&, const type&);
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friend void from_json(const nlohmann::json&, type&);
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template<typename BasicJsonType>
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friend void to_json(BasicJsonType&, const type&);
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template<typename BasicJsonType>
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friend void from_json(const BasicJsonType&, type&);
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```
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Macros 4 and 5 add two functions to the namespace which take care of the serialization and deserialization:
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```cpp
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void to_json(nlohmann::json&, const type&);
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void from_json(const nlohmann::json&, type&);
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template<typename BasicJsonType>
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void to_json(BasicJsonType&, const type&);
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template<typename BasicJsonType>
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void from_json(const BasicJsonType&, type&);
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```
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Macros 3 and 6 add one function to the namespace which take care of the serialization only:
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```cpp
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void to_json(nlohmann::json&, const type&);
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template<typename BasicJsonType>
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void to_json(BasicJsonType&, const type&);
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```
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In first two cases, they call the `to_json`/`from_json` functions of the base type
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@@ -88,12 +93,14 @@ before serializing/deserializing the members of the derived type:
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class A { /* ... */ };
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class B : public A { /* ... */ };
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void to_json(nlohmann::json& j, const B& b) {
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template<typename BasicJsonType>
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void to_json(BasicJsonType& j, const B& b) {
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nlohmann::to_json(j, static_cast<const A&>(b));
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// ...
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}
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void from_json(const nlohmann::json& j, B& b) {
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template<typename BasicJsonType>
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void from_json(const BasicJsonType& j, B& b) {
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nlohmann::from_json(j, static_cast<A&>(b));
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// ...
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}
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@@ -105,7 +112,8 @@ In the third case, only `to_json` will be called:
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class A { /* ... */ };
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class B : public A { /* ... */ };
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void to_json(nlohmann::json& j, const B& b) {
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template<typename BasicJsonType>
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void to_json(BasicJsonType& j, const B& b) {
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nlohmann::to_json(j, static_cast<const A&>(b));
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// ...
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}
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@@ -40,8 +40,10 @@ Summary:
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The macros add two friend functions to the class which take care of the serialization and deserialization:
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```cpp
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friend void to_json(nlohmann::json&, const type&);
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friend void from_json(const nlohmann::json&, type&); // except (3)
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template<typename BasicJsonType>
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friend void to_json(BasicJsonType&, const type&);
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template<typename BasicJsonType>
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friend void from_json(const BasicJsonType&, type&); // except (3)
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```
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See examples below for the concrete generated code.
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@@ -60,8 +62,6 @@ See examples below for the concrete generated code.
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- The current implementation is limited to at most 64 member variables. If you want to serialize/deserialize types
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with more than 64 member variables, you need to define the `to_json`/`from_json` functions manually.
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- The macros only work for the [`nlohmann::json`](../json.md) type; other specializations such as
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[`nlohmann::ordered_json`](../ordered_json.md) are currently unsupported.
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## Examples
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@@ -90,7 +90,7 @@ See examples below for the concrete generated code.
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The macro is equivalent to:
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```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34"
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```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34 35 36"
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--8<-- "examples/nlohmann_define_type_intrusive_explicit.cpp"
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```
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@@ -118,7 +118,7 @@ See examples below for the concrete generated code.
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The macro is equivalent to:
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```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34 35"
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```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37"
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--8<-- "examples/nlohmann_define_type_intrusive_with_default_explicit.cpp"
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```
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@@ -147,7 +147,7 @@ See examples below for the concrete generated code.
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The macro is equivalent to:
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```cpp hl_lines="22 22 23 24 25 26 27"
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```cpp hl_lines="22 22 23 24 25 26 27 28"
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--8<-- "examples/nlohmann_define_type_intrusive_only_serialize_explicit.cpp"
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```
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@@ -40,8 +40,10 @@ Summary:
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The macros add two functions to the namespace which take care of the serialization and deserialization:
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```cpp
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void to_json(nlohmann::json&, const type&);
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void from_json(const nlohmann::json&, type&); // except (3)
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template<typename BasicJsonType>
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void to_json(BasicJsonType&, const type&);
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template<typename BasicJsonType>
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void from_json(const BasicJsonType&, type&); // except (3)
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```
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See examples below for the concrete generated code.
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@@ -61,8 +63,6 @@ See examples below for the concrete generated code.
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- The current implementation is limited to at most 64 member variables. If you want to serialize/deserialize types
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with more than 64 member variables, you need to define the `to_json`/`from_json` functions manually.
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- The macros only work for the [`nlohmann::json`](../json.md) type; other specializations such as
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[`nlohmann::ordered_json`](../ordered_json.md) are currently unsupported.
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## Examples
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@@ -90,7 +90,7 @@ See examples below for the concrete generated code.
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The macro is equivalent to:
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```cpp hl_lines="16 17 18 19 20 21 22 23 24 25 26 27 28"
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```cpp hl_lines="16 17 18 19 20 21 22 23 24 25 26 27 28 29 30"
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--8<-- "examples/nlohmann_define_type_non_intrusive_explicit.cpp"
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```
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@@ -98,7 +98,7 @@ See examples below for the concrete generated code.
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Consider the following complete example:
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```cpp hl_lines="22"
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```cpp hl_lines="21"
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--8<-- "examples/nlohmann_define_type_non_intrusive_with_default_macro.cpp"
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```
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@@ -119,7 +119,7 @@ See examples below for the concrete generated code.
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The macro is equivalent to:
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```cpp hl_lines="22 23 24 25 26 27 28 29 30 31 32 33 34 35"
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```cpp hl_lines="21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36"
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--8<-- "examples/nlohmann_define_type_non_intrusive_with_default_explicit.cpp"
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```
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@@ -148,7 +148,7 @@ See examples below for the concrete generated code.
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The macro is equivalent to:
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```cpp hl_lines="16 17 18 19 20 21"
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```cpp hl_lines="16 17 18 19 20 21 22"
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--8<-- "examples/nlohmann_define_type_non_intrusive_only_serialize_explicit.cpp"
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```
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@@ -20,7 +20,7 @@ The `NLOHMANN_JSON_SERIALIZE_ENUM` allows to define a user-defined serialization
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## Default definition
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The macros add two friend functions to the class which take care of the serialization and deserialization:
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The macro adds two functions to the namespace which take care of the serialization and deserialization:
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```cpp
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template<typename BasicJsonType>
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