Cv-qualifications of prvalues during reference binding

Question

Consider this example:

const int& r2 = 5;

The rules govern reference-initialization are found in [dcl.init.ref]/5 :

A reference to type “ cv1 T1 ” is initialized by an expression of type “ cv2 T2 ” as follows:

• (5.1) [..]
• (5.2) [..]
• (5.3) Otherwise, if the initializer expression
  • (5.3.1) is an rvalue [..] and “ cv1 T1 ” is reference-compatible with “ cv2 T2 ”, or
  • (5.3.2) [..]

then the initializer expression [..] is called the converted initializer. If the converted initializer is a prvalue, its type T4 is adjusted to type “ cv1 T4 ” ([conv.qual]) and the temporary materialization conversion ([conv.rval]) is applied . In any case, the reference is bound to the resulting glvalue [..].

Here, The converted initializer is a prvalue of type T4 ( int ); then it's adjusted to cv1 T4 ( const int ). But [expr.type]/2 states:

If a prvalue initially has the type “ cv T ”, where T is a cv-unqualified non-class, non-array type, the type of the expression is adjusted to T prior to any further analysis.

One said to me that this rule ( [expr.type]/2 ) does not apply to specifically this case. And I need to know the reason behind that.

I claim that the reason for not applying [expr.type]/2 is because initially (before adjustment) the type of the prvalue is T4 ( int ) ie, it's cv-unqualified type, so [expr.type]/2 cannot be applied since the initial type of the prvalue is not cv-qualified type. Even after the adjustment to cv1 T4 , the rule [expr.type]/2 also doesn't apply because cv1 T4 is not the initial type of the prvalue. My question is : Are those correct reasons ?

Indeed both questions this and this are relatively similar but specifically I'm asking a specific, different question regarding the rule [expr.type]/2.

Answer 1

The mentioned case ( const int& r2 = 5; ) should fall into [dcl.init.ref]/(5.4.2). I think this is a mischange introduced by P0135R1 and fixed by CWG2481 .

Is it wrongly fixed?

One said to me that this rule ( [expr.type]/2 ) does not apply to specifically this case. And I need to know the reason behind that.

I think that is a non-standard comprehension of the cases addressed by CWG2481, which should be equivalent to the standard one. That is just saying "cv-qualification is not stripped".

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Perhaps the use of "rvalue" in [dcl.init.ref]/(5.3.1) is wrong unintended and the value category should be "xvalue". I'll contact CWG chair for clarification .

I'll open an editorial issue to ask whether "its type T4 is adjusted to type “ cv1 T4 ”" (5.3) and "considering the type of the prvalue to be “ cv1 T1 ”" (5.4.2) have the same meaning.