6 Statements [stmt.stmt]

6.2 Expression statement [stmt.expr]

Expression statements have the form

    expressionopt ;

The expression is a discarded-value expression (Clause [expr]). All side effects from an expression statement are completed before the next statement is executed. An expression statement with the expression missing is called a null statement. [ Note: Most statements are expression statements — usually assignments or function calls. A null statement is useful to carry a label just before the } of a compound statement and to supply a null body to an iteration statement such as a while statement ([stmt.while]).  — end note ]