Code Generation in C++

Generate code from usage

JetBrains Rider lets you use code symbols ( methods, variables, fields, and so on) before you declare them. When JetBrains Rider detects an undeclared symbol, it suggests one or more quick-fixes Alt+Enter for generating a declaration based on the usage, and then smartly adjust the declaration according to the usage context:

Generate constructors

The constructor generation wizard creates a non-default constructor that takes parameters for selected fields.

All generated constructors follow the same pattern where:

• Each field included in the constructor is initialized with a parameter.

• The name of the parameter is derived from the name of the corresponding field.

Generate missing members

This generation action creates overrides for pure virtual functions defined in the base abstract class.

Generate overriding members

This generation action creates overrides of virtual functions in a derived class:

In the Override members dialog, you will be able to choose the desired functions and configure the following preferences for the generated overrides:

• Insert 'override' specifier — you can clear this checkbox if you want to generate a function that hides the corresponding function in the base class.

• Insert 'virtual' specifier allows you to make the generated methods virtual.

Generate definitions

This generation action lets you quickly create definition stubs for all member functions that are declared in the class but have no definitions.

Copy and move operations

This generation action creates copy constructors and operator= functions that define how objects of the current class are copied and moved.

In the Generate copy and move operations dialog, you will be able to choose which base classes and class members should be taken into account when copying or moving the class objects and configure the following preferences for the generated functions:

• Access rights to allows you choose public, protected or private access modifiers.

• Copy/Move operations — these selectors allows you to choose how the operations are created. By default, the implementations of the operations are generated. However, you can generate them as Explicitly defaulted and deleted functions, only generate declarations, or skip one or another operation.

• Swap-based assignment — select this checkbox to use the swap function in the implementation of the operator=. For example,

  Rectangle& operator=(Rectangle other) { using std::swap; swap(*this, other); return *this; }

Generate getters and setters

With JetBrains Rider, you can quickly generate getter and setter functions for a class based on the existing fields:

In the Generate getters and setters dialog, you will be able to choose the desired fields and configure the following preferences for the generated functions:

• Access rights to allows you choose public, protected or private access modifiers.

• Kind allows you to choose whether getters, setters, or both should be generated.

• Accept parameters by allows you to choose how parameters should be passed to the generated setters: by const reference or by value.

• Return by allows you to choose how the generated getters should return fields: by value, reference, or const reference.

Generate equality operators

This code generation command lets you generate operator== and operator== functions that will use selected fields to compare objects of the current class.

Generate relational operators

This code generation command helps you generate operator<, operator>, operator<=, and operator>= functions that will use selected fields to compare objects of the current class.

Generate stream operations

This code generation command lets you generate the insertion operator operator<< that will use selected fields to define how to generate stream output for objects of the current class. For example:

If necessary, you can use wostream instead of ostream. To do so, select Use wide-character stream in the Generate stream operations dialog.

Another option for generating stream output is to generate stubs for Boost Serialization functions: save() and load() or serialize(). To do so, select the desired option in the Operation type selector in the Generate stream operations dialog.

Generate hash function

This code generation command lets you generate a hash function for your class. You can select one of the two hashing algorithms:

• boost::hash_combine, for example:

  #include <boost/functional/hash.hpp> ... friend std::size_t hash_value(const Rectangle& obj) { std::size_t seed = 0x315E4139; boost::hash_combine(seed, obj.width); boost::hash_combine(seed, obj.height); return seed; }

• shift and xor, for example:

  friend std::size_t hash_value(const Rectangle& obj) { std::size_t seed = 0x315E4139; seed ^= (seed << 6) + (seed >> 2) + 0x3449770D + static_cast<std::size_t>(obj.width); seed ^= (seed << 6) + (seed >> 2) + 0x49751560 + static_cast<std::size_t>(obj.height); return seed; }

Generate swap function

This code generation command lets you generate the swap function that will use selected fields to swap objects of the current class. For example: