Opaque Pointers

An opaque pointer is a pointer to a struct whose full definition is hidden from the code using it, typically by only declaring the struct's existence in a header file without listing its members. This lets a library expose functions that operate on the type while keeping its internal fields inaccessible and free to change, achieving a form of encapsulation similar to private members in object-oriented languages. Code using an opaque pointer can only interact with the underlying data through the functions the library provides.