A different sort of magic amount, although, is Employed in file formats. It truly is just a price integrated as typically the very first thing inside the file which assists detect the file format, the Variation from the file structure and/or perhaps the endian-ness of the particular file.
It absolutely was all carried out as 'pure' C++ code, using the magic of templates. There have been some work carried out to compilers to Increase the STL (I'm thinking about several optimisations) but or else, no, you could possibly publish the entire STL if you truly desired.
You regularly see magic quantities embedded in file formats, simply because documents may be despatched about alternatively promiscuously and drop any metadata about how they were being established. On the other hand magic figures will also be at times used for in-memory data buildings, like ioctl() calls.
three The Formal docs advise or else "Because the MagicMock is the more capable class it helps make a wise one to work with by default." docs.python.org/dev/library/…
Does normal goal libraries comprise any code which can't be written by standard customers? Connected
No matter whether Each and every specified implementation really uses any "magic" is a special question (you'll find parts of STL wherever "magic" would assist, although not absolutely needed).
user2916464user2916464 50122 gold badges88 silver badges1616 bronze badges one five That doesn't sound right to me. I love to use The best tool that fits my desires. Not the one particular with essentially the most bells and whistles that I don't know whether or not they are helpful or not.
What's undesirable relating to this is that you are reusing an area (that of signed integers for document IDs) for Specific talents. Perhaps you can expect to by no means want to make a report with ID 0, or having a destructive ID, but whether or not not, each individual person who seems both within the code or at the database may well stumble on this and become bewildered to start with. It goes devoid of indicating those Particular copyright values weren't properly-documented.
As a result, when attempting to find and contemplating substitute of "magic quantities" we want to inquire quite intent-filled questions about the quantities throughout the context of our software program and in some cases how the quantities interact semantically with each other.
Now, In case you are referring to the complete C++ Normal Library, then it does in fact have some "magic" in it.
AscalonianAscalonian 15k1818 gold badges7272 silver badges107107 bronze badges 2 1 I do think This could be all right In the event the constructor initializes the worth. Otherwise if the value is initialized outside of the constructor, I just see it as an inconvenience and as something more challenging to study.
Almost all of the responses to date have described a magic amount as a continuing that isn't self describing. Becoming a little bit of an "previous-school" programmer myself, back in the working day we explained magic figures as getting any continuous that's being assigned some special goal that influences the behaviour from the code.
Comparing towards ANY might be practical, such as, evaluating almost every important among two dictionaries the place some price is calculated utilizing a mock.
The beneath initial reply has become outdated. Be sure to merely Keep to the Directions denoted underneath the "dependencies" segment.