This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 116a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-12-19

964. Incorrect description of when the lvalue-to-rvalue conversion applies

[Voted into the WP at the November, 2010 meeting.]

7.2.1 [basic.lval] paragraph 7 says,

Whenever an lvalue appears in a context where an rvalue is expected, the lvalue is converted to an rvalue

That is not correct in the context of an attempt to bind an rvalue reference to an lvalue (9.4.4 [dcl.init.ref]).

Proposed resolution (October, 2009):

Change 7.2.1 [basic.lval] paragraph 7 as follows:

Whenever an lvalue appears in a context where an rvalue is expected and an lvalue is not explicitly prohibited (as, for example, in 9.4.4 [dcl.init.ref]), the lvalue it is converted to an rvalue; see 7.3.2 [conv.lval], 7.3.3 [conv.array], and 7.3.4 [conv.func].

Notes from the March, 2010 meeting:

This resolution needs to be reconsidered in light of the new expression taxonomy.

Proposed resolution (September, 2010):

Change 7.2.1 [basic.lval] paragraph 2 as follows:

Whenever a glvalue appears in a context where a prvalue is expected, the glvalue is converted to a prvalue; see 7.3.2 [conv.lval], 7.3.3 [conv.array], and 7.3.4 [conv.func]. [Note: An attempt to bind an rvalue reference to an lvalue is not such a context; see 9.4.4 [dcl.init.ref]. —end note]