Two questions about inline functions in C++

Question

I have question when I compile an inline function in C++.

Can a recursive function work with inline. If yes then please describe how.

I am sure about loop

Answer 1

One thing to keep in mind - according to the standard, inline is a suggestion, not an absolute guarantee. In the case of a recursive function, the compiler would not always be able to compute the recursion limit - modern compilers are getting extremely smart, a previous response shows the compiler evaluating a constant inline and simply generating the result, but consider

bigint fac = factorialOf(userInput)

there's no way the compiler can figure that one out........

As a side note, most compilers tend to ignore inlines in debug builds unless specifically instructed not to do so - makes debugging easier

Tail recursions can be converted to loops as long as the compiler can satisfactorily rearrange the internal representation to get the recursion conditional test at the end. In this case it can do the code generation to re-express the recursive function as a simple loop

As far as issues like tail recursion rewrites, partial expansions of recursive functions, etc, these are usually controlled by the optimization switches - all modern compilers are capable of pretty signficant optimization, but sometimes things do go wrong.