Does "(f(x))+g(y)" can make sure call f(x) first in C++?

Question

And does f(x)+(g(y)) can make sure call g(y) first? I know the order in expression is undefined in many case, but in this case does parentheses work?

Answer 1

Parentheses exist to override precedence. They have no effect on the order of evaluation.

Answer 2

Look ma, two lines!

auto r = g(y);
f(x) + r;

This introduces the all-important sequence point between the two function calls. There may be other ways to do it, but this way seems straightforward and obvious. Note that your parentheses do not introduce a sequence point, so aren't a solution.