Except as described below, a constant expression is value-dependent if any subexpression is value-dependent.
An identifier is value-dependent if it is:
a name declared with a dependent type,
the name of a non-type template parameter,
a constant with literal type and is initialized with an expression that is value-dependent.
Expressions of the following form are value-dependent if the unary-expression or expression is type-dependent or the type-id is dependent:
sizeof unary-expression sizeof ( type-id ) typeid ( expression ) typeid ( type-id ) alignof ( type-id ) noexcept ( expression )
[ Note: For the standard library macro offsetof, see [support.types]. — end note ]
Expressions of the following form are value-dependent if either the type-id or simple-type-specifier is dependent or the expression or cast-expression is value-dependent:
simple-type-specifier ( expression-listopt ) static_cast < type-id > ( expression ) const_cast < type-id > ( expression ) reinterpret_cast < type-id > ( expression ) ( type-id ) cast-expression
An id-expression is value-dependent if it names a member of an unknown specialization.