Proposed resolution (October, 2019):

Change 7.6.19 [expr.ass] paragraph 3 as follows:

The expression If the right operand is an expression, it is implicitly converted (7.3 [conv]) to the cv-unqualified type of the left operand.

Proposed resolution (May, 2019): [SUPERSEDED]

Change 7.6.19 [expr.ass] paragraph 3 as follows:

If the left operand is not of class type and the right operand is an assignment-expression, the expression assignment-expression is implicitly converted (7.3 [conv]) to the cv-unqualified type of the left operand.

[Adopted as a DR at the November, 2019 meeting.]

According to 7.6.19 [expr.ass] paragraph 3,

If the left operand is not of class type, the expression is implicitly converted (7.3 [conv]) to the cv-unqualified type of the left operand.

Since the second operand of an assignment operator can now be an initializer-clause, the referent of “expression” is unclear.

See also issue 1542.