Merge 2025-06 CWG Motion 8

P1306R5 Expansion Statements

Author: tkoeppe

source/basic.tex

@@ -1329,6 +1329,9 @@
 The locus of a \grammarterm{for-range-declaration}
 of a range-based \keyword{for} statement\iref{stmt.ranged}
 is immediately after the \grammarterm{for-range-initializer}.
+The locus of a \grammarterm{for-range-declaration}
+of an expansion statement\iref{stmt.expand}
+is immediately after the \grammarterm{expansion-initializer}.
 
 \pnum
 The locus of a \grammarterm{template-parameter} is immediately after it.
@@ -1389,7 +1392,7 @@
 Each
 \begin{itemize}
 \item
-selection or iteration statement\iref{stmt.select,stmt.iter},
+selection, iteration, or expansion statement\iref{stmt.select,stmt.iter,stmt.expand},
 \item
 substatement of such a statement,
 \item
@@ -4763,7 +4766,7 @@
 \pnum
 \indextext{initializer!temporary and declarator}%
 \indextext{temporary!order of destruction of}%
-There are five contexts in which temporaries are destroyed at a different
+There are several contexts in which temporaries are destroyed at a different
 point than the end of the full-expression.
 The first context is when a default constructor is called to initialize
 an element of an array with no corresponding initializer\iref{dcl.init}.
@@ -4883,14 +4886,25 @@
 
 \pnum
 The fourth context is when a temporary object
-is created in the \grammarterm{for-range-initializer} of a range-based \keyword{for} statement.
+is created in the \grammarterm{for-range-initializer} of
+either a range-based \keyword{for} statement
+or an enumerating expansion statement\iref{stmt.expand}.
 If such a temporary object would otherwise be destroyed
 at the end of the \grammarterm{for-range-initializer} full-expression,
 the object persists for the lifetime of the reference
 initialized by the \grammarterm{for-range-initializer}.
 
 \pnum
-The fifth context is when a temporary object
+The fifth context is when a temporary object is created
+in the \grammarterm{expansion-initializer}
+of an iterating or destructuring expansion statement.
+If such a temporary object would otherwise be destroyed
+at the end of that \grammarterm{expansion-initializer},
+the object persists for the lifetime of the reference
+initialized by the \grammarterm{expansion-initializer}, if any.
+
+\pnum
+The sixth context is when a temporary object
 is created in a structured binding declaration\iref{dcl.struct.bind}.
 Any temporary objects introduced by
 the \grammarterm{initializer}{s} for the variables

source/declarations.tex

@@ -7678,7 +7678,8 @@
 the program is ill-formed.
 
 \pnum
-If \tcode{E} is an array type with element type \tcode{T},
+\tcode{E} shall not be an array type of unknown bound.
+If \tcode{E} is any other array type with element type \tcode{T},
 the structured binding size of \tcode{E} is equal to the
 number of elements of \tcode{E}.
 Each $\textrm{SB}_i$ is the name of an

source/preprocessor.tex

@@ -2338,6 +2338,7 @@
 \defnxname{cpp_deleted_function}                  & \tcode{202403L} \\ \rowsep
 \defnxname{cpp_designated_initializers}           & \tcode{201707L} \\ \rowsep
 \defnxname{cpp_enumerator_attributes}             & \tcode{201411L} \\ \rowsep
+\defnxname{cpp_expansion_statements}              & \tcode{202506L} \\ \rowsep
 \defnxname{cpp_explicit_this_parameter}           & \tcode{202110L} \\ \rowsep
 \defnxname{cpp_fold_expressions}                  & \tcode{201603L} \\ \rowsep
 \defnxname{cpp_generic_lambdas}                   & \tcode{201707L} \\ \rowsep