[Motions 2026 06 cwg 1] P4271R0 Core Language Working Group "ready" Issues

source/basic.tex

@@ -3942,7 +3942,7 @@
 \item storage with the proper alignment and size
   for type \tcode{T} is obtained, and
 \item its initialization (if any) is complete
-  (including vacuous initialization)\iref{dcl.init},
+  (including vacuous initialization)\iref{dcl.init, class.base.init},
 \end{itemize}
 except that if the object is a union member or subobject thereof,
 its lifetime only begins if that union member is the
@@ -7618,6 +7618,7 @@
 the initialization associated with the entity for thread \placeholder{t}
 is sequenced before the first non-initialization odr-use by \placeholder{t}
 of any non-inline variable with thread storage duration
+and dynamic initialization
 defined in the same translation unit as the variable to be initialized.
 It is \impldef{threads and program points at which deferred dynamic initialization is performed}
 in which threads and at which points in the program such deferred dynamic initialization occurs.

source/classes.tex

@@ -5621,8 +5621,6 @@
 class, thus its constructors never initialize virtual base classes, therefore the
 corresponding \grammarterm{mem-initializer}{s} can be omitted.
 \end{note}
-An attempt to initialize more than one non-static data member of a union renders the
-program ill-formed.
 \indextext{initialization!const member}%
 \indextext{initialization!reference member}%
 \begin{note}
@@ -5658,6 +5656,18 @@
 \end{codeblock}
 \end{example}
 
+\pnum
+An attempt to initialize more than one non-static data member of a union renders the
+program ill-formed.
+
+\pnum
+An object's initialization is considered complete when
+a non-delegating constructor for that object returns.
+\begin{note}
+Therefore, an object's lifetime can begin\iref{basic.life}
+before all delegating constructors have completed.
+\end{note}
+
 \pnum
 If a given non-static data member has both a default member initializer
 and a \grammarterm{mem-initializer}, the initialization specified by the
@@ -6073,7 +6083,7 @@
 \end{example}
 
 \pnum
-During the construction of an object,
+During the initialization of an object,
 if the value of any of its subobjects
 or any element of its object representation
 is accessed through a glvalue that is not obtained, directly or indirectly, from

source/declarations.tex

@@ -1911,9 +1911,9 @@
 A placeholder type can also be used
 in the \grammarterm{type-specifier-seq} of
 the \grammarterm{new-type-id} or
-in the \grammarterm{type-id} of a
+in the \grammarterm{nofun-type-id} of a
 \grammarterm{new-expression}\iref{expr.new}.
-In such a \grammarterm{type-id},
+In such a \grammarterm{nofun-type-id},
 the placeholder type shall appear
 as one of the \grammarterm{type-specifier}{s} in
 the \grammarterm{type-specifier-seq} or
@@ -2288,7 +2288,7 @@
 A placeholder for a deduced class type
 can also be used
 in the \grammarterm{type-specifier-seq}
-in the \grammarterm{new-type-id} or \grammarterm{type-id}
+in the \grammarterm{new-type-id} or \grammarterm{nofun-type-id}
 of a \grammarterm{new-expression}\iref{expr.new},
 as the \grammarterm{simple-type-specifier}
 in an explicit type conversion (functional notation)\iref{expr.type.conv},
@@ -2529,7 +2529,7 @@
 
 \begin{bnf}
 \nontermdef{trailing-return-type}\br
-    \terminal{->} type-id
+    \terminal{->} nofun-type-id
 \end{bnf}
 
 \begin{bnf}
@@ -2567,20 +2567,40 @@
 
 \pnum
 \indextext{type name}%
-To specify type conversions explicitly,
 \indextext{operator!cast}%
-and as an argument of
-\tcode{sizeof},
-\tcode{alignof},
-\keyword{new},
-or
-\tcode{typeid},
-the name of a type shall be specified.
-This can be done with a
-\grammarterm{type-id} or \grammarterm{new-type-id}\iref{expr.new},
-which is syntactically a declaration for a variable or function
+A type can be named with a
+\grammarterm{type-id},
+\grammarterm{nofun-type-id}, or
+\grammarterm{new-type-id}\iref{expr.new},
+each of
+which is syntactically a declaration for a variable or
+(only for a \grammarterm{type-id}) function
 of that type that omits the name of the entity.
 
+\begin{bnf}
+\nontermdef{nofun-type-id}\br
+    type-specifier-seq \opt{nofun-declarator}
+\end{bnf}
+
+\begin{bnf}
+\nontermdef{nofun-declarator}\br
+    ptr-nofun-declarator\br
+    noptr-nofun-declarator parameters-and-qualifiers trailing-return-type
+\end{bnf}
+
+\begin{bnf}
+\nontermdef{ptr-nofun-declarator}\br
+    noptr-nofun-declarator\br
+    ptr-operator \opt{ptr-nofun-declarator}
+\end{bnf}
+
+\begin{bnf}
+\nontermdef{noptr-nofun-declarator}\br
+    noptr-nofun-declarator parameters-and-qualifiers\br
+    \opt{noptr-nofun-declarator} \terminal{[} \opt{constant-expression} \terminal{]} \opt{attribute-specifier-seq}\br
+    \terminal{(} ptr-nofun-declarator \terminal{)}
+\end{bnf}
+
 \begin{bnf}
 \nontermdef{type-id}\br
     type-specifier-seq \opt{abstract-declarator}
@@ -2625,6 +2645,7 @@
 
 It is possible to identify uniquely the location in the
 \grammarterm{abstract-declarator}
+or \grammarterm{nofun-declarator}
 where the identifier would appear if the construction were a declarator
 in a declaration.
 The named type is then the same as the type of the
@@ -2716,6 +2737,10 @@
 \grammarterm{type-id}
 in its syntactic context shall be considered a
 \grammarterm{type-id}.
+\begin{note}
+No such ambiguity can arise between an expression and
+a \grammarterm{nofun-type-id}.
+\end{note}
 However, a construct that can syntactically be a \grammarterm{type-id}
 whose outermost \grammarterm{abstract-declarator}
 would match the grammar of an \grammarterm{abstract-declarator}
@@ -2731,19 +2756,18 @@
 Y<int(1)> d;                    // expression
 
 void foo(signed char a) {
-  sizeof(int());                // \grammarterm{type-id} (ill-formed)
+  sizeof(int());                // expression
   sizeof(int(a));               // expression
-  sizeof(int(unsigned(a)));     // \grammarterm{type-id} (ill-formed)
-
-  (int())+1;                    // \grammarterm{type-id} (ill-formed)
+  sizeof(int(unsigned(a)));     // expression
+  (int())+1;                    // expression
   (int(a))+1;                   // expression
-  (int(unsigned(a)))+1;         // \grammarterm{type-id} (ill-formed)
+  (int(unsigned(a)))+1;         // expression
 }
 
 typedef struct BB { int C[2]; } *B, C;
 void g() {
   sizeof(B()->C[1]);            // OK, \tcode{\keyword{sizeof}(}expression\tcode{)}
-  sizeof(auto()->C[1]);         // error: \keyword{sizeof} of a function returning an array
+  sizeof(auto()->C[1]);         // error: ill-formed expression
 }
 \end{codeblock}
 \end{example}
@@ -9405,7 +9429,7 @@
 
 \begin{bnf}
 \nontermdef{alignment-specifier}\br
-  \keyword{alignas} \terminal{(} type-id \opt{\terminal{...}} \terminal{)}\br
+  \keyword{alignas} \terminal{(} nofun-type-id \opt{\terminal{...}} \terminal{)}\br
   \keyword{alignas} \terminal{(} constant-expression \opt{\terminal{...}} \terminal{)}
 \end{bnf}
 
@@ -9637,8 +9661,8 @@
 
 \pnum
 An \grammarterm{alignment-specifier} of the form
-\tcode{alignas(} \grammarterm{type-id} \tcode{)} has the same
-effect as \tcode{alignas(\brk{}alignof(} \grammarterm{type-id}~\tcode{))}\iref{expr.alignof}.
+\tcode{alignas(} \grammarterm{nofun-type-id} \tcode{)} has the same
+effect as \tcode{alignas(alignof(} \grammarterm{nofun-type-id}~\tcode{))}\iref{expr.alignof}.
 
 \pnum
 The alignment requirement of an entity is the strictest nonzero alignment

source/expressions.tex

@@ -5226,9 +5226,9 @@
     \terminal{--} cast-expression\br
     await-expression\br
     \keyword{sizeof} unary-expression\br
-    \keyword{sizeof} \terminal{(} type-id \terminal{)}\br
+    \keyword{sizeof} \terminal{(} nofun-type-id \terminal{)}\br
     \keyword{sizeof} \terminal{...} \terminal{(} identifier \terminal{)}\br
-    \keyword{alignof} \terminal{(} type-id \terminal{)}\br
+    \keyword{alignof} \terminal{(} nofun-type-id \terminal{)}\br
     noexcept-expression\br
     new-expression\br
     delete-expression\br
@@ -5656,7 +5656,7 @@
 occupied by a non-potentially-overlapping object of the type
 of its operand. The operand is either an expression,
 which is an unevaluated operand\iref{term.unevaluated.operand}, or a parenthesized
-\grammarterm{type-id}.
+\grammarterm{nofun-type-id}.
 \indextext{type!incomplete}%
 The \keyword{sizeof} operator shall not be applied to an expression that
 has function or incomplete type,
@@ -5747,7 +5747,7 @@
 \indextext{\idxcode{alignof}}%
 \indextext{expression!\idxcode{alignof}}%
 An \keyword{alignof} expression yields the alignment requirement
-of its operand type. The operand shall be a \grammarterm{type-id}
+of its operand type. The operand shall be a \grammarterm{nofun-type-id}
 representing a complete object type, or an array thereof, or a reference
 to one of those types.
 
@@ -5805,7 +5805,7 @@
 \indextext{storage management|see{\tcode{delete}}}%
 \indextext{\idxcode{new}}%
 The \grammarterm{new-expression} attempts to create an object of the
-\grammarterm{type-id} or \grammarterm{new-type-id}\iref{dcl.name} to which
+\grammarterm{nofun-type-id} or \grammarterm{new-type-id}\iref{dcl.name} to which
 it is applied. The type of that object is the \defnadj{allocated}{type}.
 \indextext{type!incomplete}%
 This type shall be a complete object type\iref{term.incomplete.type},
@@ -5816,14 +5816,14 @@
 \grammarterm{new-expression}{s}.
 \end{note}
 \begin{note}
-The \grammarterm{type-id} can be a cv-qualified type, in which case the
+The \grammarterm{nofun-type-id} can be a cv-qualified type, in which case the
 object created by the \grammarterm{new-expression} has a cv-qualified type.
 \end{note}
 
 \begin{bnf}
 \nontermdef{new-expression}\br
     \opt{\terminal{::}} \keyword{new} \opt{new-placement} new-type-id \opt{new-initializer} \br
-    \opt{\terminal{::}} \keyword{new} \opt{new-placement} \terminal{(} type-id \terminal{)} \opt{new-initializer}
+    \opt{\terminal{::}} \keyword{new} \opt{new-placement} \terminal{(} nofun-type-id \terminal{)} \opt{new-initializer}
 \end{bnf}
 
 \indextext{\idxcode{new}!storage allocation}%
@@ -5861,12 +5861,12 @@
 a placeholder for a deduced class type\iref{dcl.type.class.deduct}
 appears in the
 \grammarterm{type-specifier-seq} of a \grammarterm{new-type-id} or
-\grammarterm{type-id} of a \grammarterm{new-expression},
+\grammarterm{nofun-type-id} of a \grammarterm{new-expression},
 the allocated type is deduced as follows:
 Let
 \placeholder{init} be the \grammarterm{new-initializer}, if any,
 and
-\tcode{T} be the \grammarterm{new-type-id} or \grammarterm{type-id} of
+\tcode{T} be the \grammarterm{new-type-id} or \grammarterm{nofun-type-id} of
 the \grammarterm{new-expression}, then the allocated type is the type
 deduced for the variable \tcode{x} in the invented
 declaration\iref{dcl.spec.auto}:
@@ -5953,7 +5953,7 @@
 \end{example}
 
 \pnum
-If the \grammarterm{type-id} or \grammarterm{new-type-id}
+If the \grammarterm{nofun-type-id} or \grammarterm{new-type-id}
 denotes an array type of unknown bound\iref{dcl.array},
 the \grammarterm{new-initializer} shall not be omitted;
 the allocated object is an array with \tcode{n} elements,
@@ -6053,7 +6053,7 @@
 \indextext{array!\idxcode{new}}%
 When the allocated type is ``array of \tcode{N} \tcode{T}''
 (that is, the \grammarterm{noptr-new-declarator} syntax is used or the
-\grammarterm{new-type-id} or \grammarterm{type-id} denotes an array type),
+\grammarterm{new-type-id} or \grammarterm{nofun-type-id} denotes an array type),
 the \grammarterm{new-expression} yields a prvalue of type ``pointer to \tcode{T}''
 that points to the initial element (if any) of the array.
 Otherwise, let \tcode{T} be the allocated type;
@@ -6996,7 +6996,7 @@
 \begin{bnf}
 \nontermdef{cast-expression}\br
     unary-expression\br
-    \terminal{(} type-id \terminal{)} cast-expression
+    \terminal{(} nofun-type-id \terminal{)} cast-expression
 \end{bnf}
 
 \pnum

source/templates.tex

@@ -5834,6 +5834,7 @@
 Expressions of the following forms are type-dependent only if the type
 specified by the
 \grammarterm{type-id},
+\grammarterm{nofun-type-id},
 \grammarterm{simple-type-specifier},
 \grammarterm{typename-specifier},
 or
@@ -5846,12 +5847,12 @@
 typename-specifier \terminal{(} \opt{expression-list} \terminal{)}\br
 typename-specifier braced-init-list\br
 \opt{\terminal{::}} \keyword{new} \opt{new-placement} new-type-id \opt{new-initializer}\br
-\opt{\terminal{::}} \keyword{new} \opt{new-placement} \terminal{(} type-id \terminal{)} \opt{new-initializer}\br
+\opt{\terminal{::}} \keyword{new} \opt{new-placement} \terminal{(} nofun-type-id \terminal{)} \opt{new-initializer}\br
 \keyword{dynamic_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br
 \keyword{static_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br
 \keyword{const_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br
 \keyword{reinterpret_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br
-\terminal{(} type-id \terminal{)} cast-expression
+\terminal{(} nofun-type-id \terminal{)} cast-expression
 \end{ncsimplebnf}
 
 \pnum
@@ -5861,9 +5862,9 @@
 \begin{ncsimplebnf}
 literal\br
 \keyword{sizeof} unary-expression\br
-\keyword{sizeof} \terminal{(} type-id \terminal{)}\br
+\keyword{sizeof} \terminal{(} nofun-type-id \terminal{)}\br
 \keyword{sizeof} \terminal{...} \terminal{(} identifier \terminal{)}\br
-\keyword{alignof} \terminal{(} type-id \terminal{)}\br
+\keyword{alignof} \terminal{(} nofun-type-id \terminal{)}\br
 \keyword{typeid} \terminal{(} expression \terminal{)}\br
 \keyword{typeid} \terminal{(} type-id \terminal{)}\br
 \opt{\terminal{::}} \keyword{delete} cast-expression\br
@@ -5967,14 +5968,15 @@
 \grammarterm{unary-expression} or \grammarterm{expression}
 is type-dependent or the
 \grammarterm{type-id}
+or \grammarterm{nofun-type-id}
 is dependent:
 
 \begin{ncsimplebnf}
 \keyword{sizeof} unary-expression\br
-\keyword{sizeof} \terminal{(} type-id \terminal{)}\br
+\keyword{sizeof} \terminal{(} nofun-type-id \terminal{)}\br
 \keyword{typeid} \terminal{(} expression \terminal{)}\br
 \keyword{typeid} \terminal{(} type-id \terminal{)}\br
-\keyword{alignof} \terminal{(} type-id \terminal{)}
+\keyword{alignof} \terminal{(} nofun-type-id \terminal{)}
 \end{ncsimplebnf}
 
 \begin{note}
@@ -5985,6 +5987,7 @@
 \pnum
 Expressions of the following form are value-dependent if either the
 \grammarterm{type-id},
+\grammarterm{nofun-type-id},
 \grammarterm{simple-type-specifier}, or
 \grammarterm{typename-specifier}
 is dependent or the
@@ -6006,7 +6009,7 @@
 \keyword{const_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br
 \keyword{reinterpret_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br
 \keyword{dynamic_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br
-\terminal{(} type-id \terminal{)} cast-expression
+\terminal{(} nofun-type-id \terminal{)} cast-expression
 \end{ncsimplebnf}
 
 \pnum