Exercise 4.20 of C++ Primer, 5e asks whether the expression iter++->empty(); is legal. Assume that iter is a vector<string>::iterator.
This expression is legal. I compiled it with gcc, and the answers to another question on Stack Overflow have addressed this much. However, I'm confused as to why it is legal.
This answer to a similar question gives the following as an equivalent pair of expressions:
iter->empty();
iter++;
The operator precedence table in my book lists -> as having higher precedence than the postfix ++ operator. This matches the explicit order of operations in the equivalent code above. However, I am used to seeing operators apply to whatever is right next to them. In the case of ->, I expected the compiler would to apply it to ++ (by itself, without iter) and throw an error. In other words, I tried to parenthesize the original expression as iter(++->empty());, which is obviously illegal.
So, it seems like c++ requires compilers to parse expressions in a more complex way than just parenthesizing based on precedence and associativity. Is that right? If there is an easy way to explain how this actually happens, I would like to know about it.