Can you declare every function with the inline keyword in a program?

In the Kotlin language (commonly used in Android development), the keyword inline can be used for functions so that the compiler inserts the function body directly at the call sites, reducing the overhead of function calls.

However, declaring every function as inline is not recommended and often impossible:

• inline functions should be small, otherwise the size of the final code will increase significantly.
• Functions with large bodies or complex logic are inefficient to make inline.
• Some functions, such as virtual functions or those with certain modifiers, cannot be inline.

Therefore, inline should be used selectively, for small functions, especially for higher-order functions, to avoid creating additional objects and to improve performance.