All preprocessor commands begins with the hash (pound) symbol
A C macro is just a preprocessor command that is defined using the
#define preprocessor directive. During the preprocessing stage, the C preprocessor (a part of the C compiler) simply substitutes the body of the macro wherever its name appears.
X-macros are a preprocessor-based technique for minimizing repetitious code and maintaining data / code correspondences. Multiple distinct macro expansions based on a common set of data are supported by representing the whole group of expansions via a single master macro, with that macro's replacement text consisting of a sequence of expansions of an inner macro, one for each datum. The inner macro is traditionally named
X(), hence the name of the technique.
We have new features for Eloquent Relationship in Laravel version 5.4.8. We can fetch a single instance of a hasMany (it is just one example) relationship by define it at on place and it will works for all relationship
Rust 1.15 added (stabilized) a new feature: Custom derive aka Macros 1.1.
Rust Book link: https://doc.rust-lang.org/stable/book/procedural-macros.html
Also known as arrow macros, threading macros convert nested function calls into a linear flow of function calls.