cpp/numeric/valarray/operator arith2

Applies compound assignment operators to each element in the numeric array.

@1@ Each element is assigned value obtained by applying the corresponding operator to the previous value of the element and corresponding element from.

@@ The behavior is undefined if

@@ The behavior is undefined if any of the values in is computed during the assignment and depends on any of the values in, that is, the expression on the right side of the assignment refers to a variable in the left side of the assignment.

@2@ Each element is assigned value obtained by applying the corresponding operator to the previous value of the element and the value of.