29 // basic.lval/1 Every expression is either an lvalue or an rvalue.
34 // an lvalue.
39     static_assert(__is_lvalue_expr(expr), "should be an lvalue");       \
43     static_assert(!__is_rvalue_expr(expr), "should be an lvalue");      \
49     static_assert(__is_rvalue_expr(expr), "should be an rvalue");       \
53     static_assert(!__is_lvalue_expr(expr), "should be an rvalue");      \
67     // a reference is an rvalue.  in basic_lval_5()
78     // basic.lval/6: An expression which holds a temporary object resulting  in basic_lval_6()
79     // from a cast to a nonreference type is an rvalue (this includes  in basic_lval_6()
80     // the explicit creation of an object using functional notation  in basic_lval_6()
131     // conv.ptr/1: A null pointer constant is an integral constant  in conv_ptr_1()
139     // expr/6: If an expression initially has the type "reference to T"  in expr_6()
140     // (8.3.2, 8.5.3), ... the expression is an lvalue.  in expr_6()
149     // 5.1/2 A string literal is an lvalue; all other  in expr_prim_2()
161     // expression is an rvalue.  in expr_prim_3()
216         // 5.1/4: The operator :: followed by an identifier, a  in expr_prim_4()
217         // qualified-id, or an operator-function-id is a primary-  in expr_prim_4()
218         // expression. ...The result is an lvalue if the entity is  in expr_prim_4()
250         // expr.prim/7 An identifier is an id-expression provided it has been  in expr_prim_7()
253         // entity denoted by the identifier. The result is an lvalue if  in expr_prim_7()
266         // member. The result is an lvalue if the member is a static  in expr_prim_7()
280     // expr.call/10: A function call is an lvalue if and only if the  in expr_call_10()
303     // member. The result is an lvalue if the member is a function or  in expr_prim_8()
311     // expr.sub/1 A postfix expression followed by an expression in  in expr_sub_1()
314     // enumeration or integral type. The result is an lvalue of type  in expr_sub_1()
331     // being the value of t as an rvalue.  in expr_type_conv_1()
339     // type or the (possibly cv-qualified) void type, creates an  in expr_type_conv_2()
352     // an lvalue;.... Otherwise, one of the following rules applies.  in expr_ref_4()
357     // E1.E2 is an lvalue; ...  in expr_ref_4()
362     // - If E2 is a non-static data member, ... If E1 is an lvalue,  in expr_ref_4()
363     // then E1.E2 is an lvalue...  in expr_ref_4()
369     // is an lvalue  in expr_ref_4()
373     // then E1.E2 is not an lvalue.  in expr_ref_4()
377     // expression E1.E2 is not an lvalue. The type of E1.E2 is T.  in expr_ref_4()
387     // operator... The result is an rvalue.  in expr_post_incr_1()
393     // expr.dynamic.cast/2: If T is a pointer type, v shall be an  in expr_dynamic_cast_2()
395     // an rvalue of type T.  in expr_dynamic_cast_2()
399     // If T is a reference type, v shall be an  in expr_dynamic_cast_2()
400     // lvalue of a complete class type, and the result is an lvalue of  in expr_dynamic_cast_2()
408     // "cv2 D" such that B is a base class of D, the result is an  in expr_dynamic_cast_5()
422 // (referred) to by v, the result is a pointer (an lvalue referring)
428 // result is a pointer (an lvalue referring) to the T sub-object of
438     // expr.typeid/1: The result of a typeid expression is an lvalue...
447     // to type T. If T is a reference type, the result is an lvalue;  in expr_static_cast_1()
448     // otherwise, the result is an rvalue.  in expr_static_cast_1()
458     // an lvalue; otherwise, the result is an rvalue  in expr_reinterpret_cast_1()
467     // expression to which it is applied shall be a pointer to an  in expr_unary_op_1()
469     // an lvalue referring to the object or function to which the  in expr_unary_op_1()
474     // [Note: a pointer to an incomplete type  in expr_unary_op_1()
483     // operand; it is an lvalue.  in expr_pre_incr_1()
490     // is of type T. The result is an lvalue if T is a reference type,  in expr_cast_1()
491     // otherwise the result is an rvalue.  in expr_cast_1()
500     // expr.mptr.oper/6: The result of a .* expression is an lvalue  in expr_mptr_oper()
501     // only if its first operand is an lvalue and its second operand  in expr_mptr_oper()
510     // (cont'd)...The result of an ->* expression is an lvalue only  in expr_mptr_oper()
538     // is of type void and is an rvalue. [Note: this includes the case  in expr_cond()
544     // have the same type, the result is of that type and is an  in expr_cond()
550     // expr.cond/5:Otherwise, the result is an rvalue.  in expr_cond()
563     // their left operand, and the type of an assignment expression is  in expr_ass_1()
566     // assignment has taken place; the result is an lvalue.  in expr_ass_1()
582     // discarded... result is an lvalue if its right operand is.  in expr_comma()
586     static_assert(__is_lvalue_expr(x,x), "expected an lvalue");  in expr_comma()
587     static_assert(__is_rvalue_expr(x,1), "expected an rvalue");  in expr_comma()
588     static_assert(__is_lvalue_expr(1,x), "expected an lvalue");  in expr_comma()
589     static_assert(__is_rvalue_expr(1,1), "expected an rvalue");  in expr_comma()