6.5.16 Assignment operators

assignment-expression:
                conditional-expression
                unary-expression assignment-operator assignment-expression

assignment-operator: one of
                =  *=  /=  %=  +=  -=  <<=  >>=  &=  ^=  |=

1279 An assignment operator shall have a modifiable lvalue as its left operand.

1280 An assignment operator stores a value in the object designated by the left operand.

1281 An assignment expression has the value of the left operand after the assignment, but is not an lvalue.

1282 The type of an assignment expression is the type of the left operand unless the left operand has qualified type, in which case it is the unqualified version of the type of the left operand.

1283 The side effect of updating the stored value of the left operand shall occur between the previous and the next sequence point.

1284 The order of evaluation of the operands is unspecified.

1285 If an attempt is made to modify the result of an assignment operator or to access it after the next sequence point, the behavior is undefined.