The full context to that second quote is: > When a function is called, each parameter ([dcl.fct]) shall be initialized ([dcl.init], [class.copy], [class.ctor])

The full context to that second quote is: > When a function is called, each parameter ([dcl.fct]) shall be initialized ([dcl.init], [class.copy], [class.ctor]) with its corresponding argument. [ Note: Such initializations are indeterminately sequenced with respect to each other ([intro.execution]) — end note ] So it's only about initialisation of parameters from arguments, not to the evaluation of arguments. (For example if foo() takes a std::string parameter, and bar() returns a const char*, then in the expression foo(bar()) the above quote refers to the call to the string constructor, not to the call to bar().) The more relevant part is 5.2.2/8: > [ Note: The evaluations of the postfix expression and of the argument expressions are all unsequenced relative to one another. All side effects of argument expression evaluations are sequenced before the function is entered (see [intro.execution]). — end note ]