NFD code style guidelines¶

NFD adopts NDN Platform C++, C, C#, Java and JavaScript Code Guidelines, with the following exceptions:

• (amended 10)
  Global variables should have g_ prefix

• (amended 11)
  All class variables should have m_ prefix.
  Static class variables should have s_ prefix.

• (amended 31)
  Exceptions can be used in the code, but should be used only in exceptional cases and not in the primary processing path.

  Exceptions can be suffixed with either Exception (eg. SecurityException) or Error (eg. SecurityError). Alternatively (and it is a recommended method), one should declare exception class Exception or Error as an inner class, from which the exception is thrown. For example, when declaring class Foo that can throw errors, one can write the following:

  #include <stdexcept>
  
  class Foo
  {
      struct Error : std::runtime_exception
      {
          Error(const std::string& what) : std::runtime_error(what) {}
      };
  };
  

  In addition to that, if class Foo is a base class or interface for some class hierarchy, then child classes should should define their own Error or Exception classes that are inherited from the parent's Error class.

• (amended 33)
  We will use only .cpp and .hpp extensions

• (removed 35)
  Lines should be within a reasonable range. >100 column-lines should be generally avoided.

• (removed 44)
  Implicit conversion is generally allowed.

  Implicit conversion between integer and floating point numbers can cause problems and should be avoided.

  Implicit conversion in single-argument constructor is usually undesirable. Therefore, all single-argument constructors should be marked 'explicit', unless implicit conversion is desirable. In that case, a comment should document the reason.

  Avoid C-style casts. Use static_cast, dynamic_cast, reinterpret_cast, const_cast instead where appropriate.

• (amended 68)
  All three presented styles ARE acceptable. First and third ARE recommended (these are actually GNU styles).

• (amended 69)
  The class declarations should have the following form:

  class SomeClass : public BaseClass 
  { 
  public: 
    ... <public methods> ...
  protected: 
    ... <protected methods> ...
  private: 
    ... <private methods> ...
  
  public: 
    ... <public data> ...
  protected: 
    ... <protected data> ...
  private: 
    ... <private data> ...
  };
  

  public, protected, private may be repeated several times without interleaving (e.g. public, public, public, private, private) if this allows better readability of the code.

• (amended 70)
  When declaring/defining function/method, the return type should be put on a separate line before function/method name.

  Method and function definitions should have the following form:

  void
  someMethod() 
  { 
    ... 
  }