"inline" is confusing in C++, as it is not really about inlining. Its purpose is to allow multiple definitions of the same function. It is useful when you have a function defined in a header file, because if included in several source files, it will be present in multiple object files, and without "inline" the linker will complain of multiple definitions.
It is also an optimization hint, but AFAIK, modern compiler ignore it.
It is also an optimization hint, but AFAIK, modern compiler ignore it.