Merge 2022-02 CWG Motion 1

P2533R0 Core Language Working Group "ready" Issues for the February, 2022 Meeting

Author: tkoeppe

source/basic.tex

@@ -329,11 +329,22 @@
 \indextext{enumerator!definition}%
 \indextext{one-definition rule|(}%
 
+\pnum
+Each of the following is termed a \defnadj{definable}{item}:
+\begin{itemize}
+\item a class type\iref{class},
+\item an enumeration type\iref{dcl.enum},
+\item a function\iref{dcl.fct},
+\item a variable\iref{basic.pre},
+\item a templated entity\iref{temp.pre},
+\item a default argument for a parameter
+(for a function in a given scope)\iref{dcl.fct.default}, or
+\item a default template argument\iref{temp.param}.
+\end{itemize}
+
 \pnum
 No translation unit shall contain more than one definition of any
-variable, function, class type, enumeration type, template,
-default argument for a parameter (for a function in a given scope), or
-default template argument.
+definable item.
 
 \pnum
 \indextext{expression!potentially evaluated}%
@@ -527,7 +538,7 @@
 \end{example}
 
 \pnum
-Every program shall contain exactly one definition of every non-inline
+Every program shall contain at least one definition of every
 function or variable that is odr-used in that program
 outside of a discarded statement\iref{stmt.if}; no diagnostic required.
 The definition can appear explicitly in the program, it can be found in
@@ -611,20 +622,19 @@
 \end{note}
 
 \pnum
-There can be more than one definition of a
+For any definable item \tcode{D} with definitions in multiple translation units,
 \begin{itemize}
-\item class type\iref{class},
-\item enumeration type\iref{dcl.enum},
-\item inline function or variable\iref{dcl.inline},
-\item templated entity\iref{temp.pre},
-\item default argument for a parameter (for a function in a given scope)%
-\iref{dcl.fct.default}, or
-\item default template argument\iref{temp.param}
+\item
+if \tcode{D} is a non-inline non-templated function or variable, or
+\item
+if the definitions in different translation units
+do not satisfy the following requirements,
 \end{itemize}
-in a program provided that
-each definition appears in a different translation unit and
-the definitions satisfy the following requirements.
-Given such an entity \tcode{D} defined in more than one translation unit,
+the program is ill-formed;
+a diagnostic is required only
+if the definable item is attached to a named module and
+a prior definition is reachable at the point where a later definition occurs.
+Given such an item,
 for all definitions of \tcode{D}, or,
 if \tcode{D} is an unnamed enumeration,
 for all definitions of \tcode{D} that are reachable at any given program point,
@@ -745,13 +755,6 @@
 might still denote different types in different translation units.
 \end{note}
 
-\pnum
-If these definitions do not satisfy these requirements,
-then the program is ill-formed;
-a diagnostic is required only if
-the entity is attached to a named module and
-a prior definition is reachable at the point where a later definition occurs.
-
 \pnum
 \begin{example}
 \begin{codeblock}
@@ -1222,7 +1225,8 @@
 \grammarterm{compound-statement} of a \grammarterm{lambda-expression},
 \grammarterm{function-body}, or \grammarterm{function-try-block},
 \item
-substatement of a selection or iteration statement, or
+substatement of a selection or iteration statement
+that is not itself a selection or iteration statement, or
 \item
 \grammarterm{handler} of a \grammarterm{function-try-block}
 \end{itemize}
@@ -5179,8 +5183,7 @@
 the other is a non-static data member of that object\iref{class.union}, or
 \item
 one is a standard-layout class object and
-the other is the first non-static data member of that object, or,
-if the object has no non-static data members,
+the other is the first non-static data member of that object or
 any base class subobject of that object\iref{class.mem}, or
 \item
 there exists an object \placeholder{c} such that

source/classes.tex

@@ -2472,8 +2472,6 @@
 \indextext{fundamental type conversion|see{conversion, user-defined}}%
 \indextext{conversion!user-defined}%
 
-\pnum
-A member function of a class \tcode{X} with a name of the form
 \begin{bnf}
 \nontermdef{conversion-function-id}\br
     \keyword{operator} conversion-type-id
@@ -2488,18 +2486,52 @@
 \nontermdef{conversion-declarator}\br
     ptr-operator \opt{conversion-declarator}
 \end{bnf}
-shall have no non-object parameters and
-specifies a conversion from \tcode{X} to
+
+\pnum
+A declaration
+whose \grammarterm{declarator-id} has
+an \grammarterm{unqualified-id} that is a \grammarterm{conversion-function-id}
+declares a \defnadj{conversion}{function};
+its \grammarterm{declarator} shall be
+a function declarator\iref{dcl.fct} of the form
+\begin{ncsimplebnf}
+ptr-declarator \terminal{(} parameter-declaration-clause \terminal{)} \opt{cv-qualifier-seq}\br
+\bnfindent \opt{ref-qualifier-seq} \opt{noexcept-specifier} \opt{attribute-specifier-seq}
+\end{ncsimplebnf}
+where the \grammarterm{ptr-declarator} consists solely of
+an \grammarterm{id-expression},
+an optional \grammarterm{attribute-specifier-seq}, and
+optional surrounding parentheses, and
+the \grammarterm{id-expression} has one of the following forms:
+\begin{itemize}
+\item
+in a \grammarterm{member-declaration} that belongs to
+the \grammarterm{member-specification} of a class or class template
+but is not a friend declaration\iref{class.friend},
+the \grammarterm{id-expression} is a \grammarterm{conversion-function-id};
+\item
+otherwise, the \grammarterm{id-expression} is a \grammarterm{qualified-id}
+whose \grammarterm{unqualified-id} is a \grammarterm{conversion-function-id}.
+\end{itemize}
+
+\pnum
+A conversion function  shall have no non-object parameters and
+shall be a non-static member function of a class or class template \tcode{X};
+it specifies a conversion from \tcode{X} to
 the type specified by the \grammarterm{conversion-type-id},
 interpreted as a \grammarterm{type-id}\iref{dcl.name}.
-Such functions are called \defnx{conversion functions}{conversion function}.
 A \grammarterm{decl-specifier} in the \grammarterm{decl-specifier-seq}
-of a conversion function (if any) shall be neither
-a \grammarterm{defining-type-specifier} nor \keyword{static}.
+of a conversion function (if any) shall not be
+a \grammarterm{defining-type-specifier}.
+
+\pnum
 \indextext{conversion!type of}%
-The type of the conversion function\iref{dcl.fct} is
-``function taking no parameter returning
-\grammarterm{conversion-type-id}''.
+The type of the conversion function is
+``\opt{\tcode{noexcept}} function taking no parameter
+\opt{\grammarterm{cv-qualifier-seq}} \opt{\grammarterm{ref-qualifier}}
+returning \grammarterm{conversion-type-id}''.
+
+\pnum
 A conversion function is never used to convert a (possibly cv-qualified) object
 to the (possibly cv-qualified) same object type (or a reference to it),
 to a (possibly cv-qualified) base class of that type (or a reference to it),
@@ -2783,7 +2815,7 @@
 to the entity being declared.
 A bit-field shall not be a static member.
 \indextext{bit-field!type of}%
-A bit-field shall have integral or enumeration type;
+A bit-field shall have integral or (possibly cv-qualified) enumeration type;
 the bit-field semantic property is not part of the type of the class member.
 The \grammarterm{constant-expression} shall be an integral constant expression
 with a value greater than or equal to zero and

source/declarations.tex

@@ -6714,7 +6714,7 @@
 see~\ref{depr.volatile.type}.
 First, a variable with a unique name \exposid{e} is introduced. If the
 \grammarterm{assignment-expression} in the \grammarterm{initializer}
-has array type \tcode{A} and no \grammarterm{ref-qualifier} is present,
+has array type \cvqual{cv1} \tcode{A} and no \grammarterm{ref-qualifier} is present,
 \exposid{e} is defined by
 \begin{ncbnf}
 \opt{attribute-specifier-seq} \placeholder{S} \cv{} \terminal{A} \exposid{e} \terminal{;}

source/expressions.tex

@@ -1690,7 +1690,20 @@
 
 \begin{bnf}
 \nontermdef{lambda-specifiers}\br
-    \opt{decl-specifier-seq} \opt{noexcept-specifier} \opt{attribute-specifier-seq} \opt{trailing-return-type}
+    \opt{lambda-specifier-seq} \opt{noexcept-specifier} \opt{attribute-specifier-seq} \opt{trailing-return-type}
+\end{bnf}
+
+\begin{bnf}
+\nontermdef{lambda-specifier}\br
+    \keyword{consteval}\br
+    \keyword{constexpr}\br
+    \keyword{mutable}
+\end{bnf}
+
+\begin{bnf}
+\nontermdef{lambda-specifier-seq}\br
+    lambda-specifier\br
+    lambda-specifier lambda-specifier-seq
 \end{bnf}
 
 \pnum
@@ -1715,12 +1728,12 @@
 \end{note}
 
 \pnum
-In the \grammarterm{decl-specifier-seq} of the \grammarterm{lambda-declarator},
-each \grammarterm{decl-specifier}
-shall be one of \keyword{mutable}, \keyword{constexpr}, or \keyword{consteval}.
+A \grammarterm{lambda-specifier-seq}
+shall contain at most one of each \grammarterm{lambda-specifier} and
+shall not contain both \keyword{constexpr} and \keyword{consteval}.
 If the \grammarterm{lambda-declarator} contains
 an explicit object parameter\iref{dcl.fct},
-then no \grammarterm{decl-specifier} in the \grammarterm{decl-specifier-seq}
+then no \grammarterm{lambda-specifier} in the \grammarterm{lambda-specifier-seq}
 shall be \keyword{mutable}.
 \begin{note}
 The trailing \grammarterm{requires-clause} is described in \ref{dcl.decl}.