Compiler Hint: “Inline function '…' has not been expanded…”

Question

In a unit I use the function DeleteFile and the compiler outputs a hint:

\"H2443 Inline function \'DeleteFile\' has not been expanded because

Answer 1

Inline functions are expanded in place by the compiler, avoiding the overhead of a function call. E.g. for squaring, sqr(x) is compiled in as x*x rather than calling a function that multiplies x and returns the result.