You just run a command like this in the terminal it should print out a guid: Pretty much all linux systems have built-in UUID implementations. This code with any build system, I'll just use a series of super ugly #ifdefs There will be another class named GuidGenerator which will need to have someĬustom code for each operating system. The implementations of all the functions prototyped above can be generic, but It also supports // conversion to string (via the stream operator & bytes ) // create a guid from array of bytes Guid ( const unsigned char * bytes ) // create a guid from string Guid ( const string & fromString ) // create empty guid Guid () // copy constructor Guid ( const Guid & other ) // overload assignment operator Guid & operator = ( const Guid & other ) // overload equality and inequality operator bool operator = ( const Guid & other ) const bool operator != ( const Guid & other ) const private : // actual data vector _bytes // make the << operator a friend so it can access _bytes friend ostream & operator << ( ostream & s, const Guid & guid ) } Each instance acts as a wrapper around a // 16 byte value that can be passed around by value. Is easier to pronounce and I think it looks nicer in pascal case. In the generic interface I will use GUID because it GUID or UUID since the Windows world tends to use the term GUID while the unix That there is no way for me to be completely consistent in my use of either Common interfaceįirst let's define an operating system agnostic class for our identifiers. Of a sudden you have a ton of extra dependencies. I generally avoidīoost because boost modules tend to depend on other boost modules and then all Implementation that was sufficiently generic and minimal. I am implementing this from scratch because I couldn't find any existing There should also be no dependencies on any non-standard Which utilizes this UUID library can ignore the underlying system Use some form of conditional compilation so that we can have slightly differentĬode depending on the OS, and we will need some wrapper so that external code Half-baked implementations that may be flawed. Method of UUID generation on each system instead of using any risky, untested, GoalĬreate a very small implementation that utilizes the best, most standardized Their own GUIDs you want the server to do all the GUID generation.Ĭ++: I mean actual modern C++ where possible, not just C with classes. Probably don't want third party consumers of your API to be allowed to generate GUIDs for identifiers and an ID collision would break the system, then you For example, if you have an API where you can create entities with If ID conflicts can break your system or create securityĬoncerns then GUIDs are not for you unless you can complete control over their Other properly generated unique identifiers. Values themselves are 128 bits of data that are guaranteed to be unique among For our purposes we can consider them synonyms. Guaranteed to be unique of we combine values from across the galaxy, the realĭifferentiation is that GUID refers to various implementations of the UUID Although the names imply that a GUID is not UUID/GUID: UUID stands for Universally Unique Identifier and GUID standsįor Globally Unique Identifier. Windows, Linux, Mac OS, Android, and iOS. The implementation should alsoĪvoid unnecessary abstraction so that there are fewer lines of code and anyoneĬan quickly read the implementation to see clearly what it is doing.Ĭross platform: Works on all major operating systems. It should also be trivial to source embed the module Minimalist: The amount of code will have a negligible affect on compile Will probably not update the snippets in this article. Over time I will like make updates and bug fixes to the git repository, but I
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