Merge 2020-11 LWG Motion 3

Author: tkoeppe

source/algorithms.tex

@@ -262,11 +262,12 @@
 that takes separate iterator and sentinel arguments.
 
 \pnum
-The number and order of deducible template parameters for algorithm declarations
-are unspecified, except where explicitly stated otherwise.
+The well-formedness and behavior of a call to an algorithm with
+an explicitly-specified template argument list
+is unspecified, except where explicitly stated otherwise.
 \begin{note}
-Consequently, an implementation can reject calls
-that specify an explicit template argument list.
+Consequently, an implementation can declare an algorithm with
+different template parameters than those presented.
 \end{note}
 
 \rSec1[algorithms.parallel]{Parallel algorithms}

source/atomics.tex

@@ -626,10 +626,11 @@
 \end{note}
 
 \pnum
-The function \tcode{atomic_is_lock_free}\iref{atomics.types.operations}
-indicates whether the object is lock-free. In any given program execution, the
-result of the lock-free query shall be consistent for all pointers of the same
-type.
+The functions \tcode{atomic<T>::is_lock_free} and
+\tcode{atomic_is_lock_free}\iref{atomics.types.operations}
+indicate whether the object is lock-free. In any given program execution, the
+result of the lock-free query
+is the same for all atomic objects of the same type.
 
 \pnum
 Atomic operations that are not lock-free are considered to potentially

source/concepts.tex

@@ -331,8 +331,8 @@
 
 \pnum
 Given types \tcode{From} and \tcode{To} and
-an expression \tcode{E} such that
-\tcode{decltype((E))} is \tcode{add_rvalue_reference_t<From>},
+an expression \tcode{E}
+whose type and value category are the same as those of \tcode{declval<From>()},
 \tcode{\libconcept{convertible_to}<From, To>} requires \tcode{E}
 to be both implicitly and explicitly convertible to type \tcode{To}.
 The implicit and explicit conversions are required to produce equal
@@ -907,7 +907,7 @@
 A \defnadj{key}{parameter} of a function template \tcode{D}
 is a function parameter of type \cv{} \tcode{X} or reference thereto,
 where \tcode{X} names a specialization of a class template that
-is a member of the same namespace as \tcode{D}, and
+has the same innermost enclosing non-inline namespace as \tcode{D}, and
 \tcode{X} contains at least one template parameter that
 participates in template argument deduction.
 \begin{example}

source/containers.tex

@@ -179,8 +179,9 @@
 \tcode{a = rv}              &
   \tcode{X\&}               &
   All existing elements of \tcode{a} are either move assigned to or destroyed   &
-  \ensures \tcode{a} is equal to the value that \tcode{rv}
-  had before this assignment   &
+  \ensures If \tcode{a} and \tcode{rv} do not refer to the same object,
+  \tcode{a} is equal to the value that \tcode{rv}
+  had before this assignment.   &
    linear                     \\ \rowsep
 
 \tcode{a.\~X()}    &
@@ -707,7 +708,8 @@
   \oldconcept{MoveAssignable}.\br
   \effects All existing elements of \tcode{a}
   are either move assigned to or destroyed.\br
-  \ensures \tcode{a} is equal to the value that \tcode{rv} had before
+  \ensures If \tcode{a} and \tcode{rv} do not refer to the same object,
+  \tcode{a} is equal to the value that \tcode{rv} had before
   this assignment.      &
   linear                \\ \rowsep
 
@@ -1274,11 +1276,12 @@
   using allocator_type = @\seebelownc{}@;
 
 private:
-  using container_node_type = @\unspecnc@;
-  using ator_traits = allocator_traits<allocator_type>;
+  using container_node_type = @\unspecnc@;                  // \expos
+  using ator_traits = allocator_traits<allocator_type>;     // \expos
 
-  typename ator_traits::template rebind_traits<container_node_type>::pointer ptr_;
-  optional<allocator_type> alloc_;
+  typename ator_traits::template
+    rebind_traits<container_node_type>::pointer ptr_;       // \expos
+  optional<allocator_type> alloc_;                          // \expos
 
 public:
   // \ref{container.node.cons}, constructors, copy, and assignment

source/future.tex

@@ -1514,6 +1514,50 @@
 \tcode{rdbuf()->pcount()}.
 \end{itemdescr}
 
+\rSec1[depr.default.allocator]{The default allocator}
+
+\pnum
+The following member is defined in addition to those
+specified in \ref{default.allocator}:
+
+\begin{codeblock}
+namespace std {
+  template<class T> class allocator {
+  public:
+    using is_always_equal = true_type;
+  };
+}
+\end{codeblock}
+
+\rSec1[depr.mem.poly.allocator.mem]{Deprecated \tcode{polymorphic_allocator} member function}
+
+\pnum
+The following member is declared in addition to those members
+specified in \ref{mem.poly.allocator.mem}:
+
+\begin{codeblock}
+namespace std::pmr {
+  template<class Tp = byte>
+  class polymorphic_allocator {
+  public:
+    template <class T>
+      void destroy(T* p);
+  };
+}
+\end{codeblock}
+
+\indexlibrarymember{destroy}{polymorphic_allocator}%
+\begin{itemdecl}
+template<class T>
+  void destroy(T* p);
+\end{itemdecl}
+
+\begin{itemdescr}
+\pnum
+\effects
+As if by \tcode{p->\~T()}.
+\end{itemdescr}
+
 \rSec1[depr.meta.types]{Deprecated type traits}
 
 \pnum

source/iostreams.tex

@@ -1604,6 +1604,7 @@
 member function called from within
 \tcode{fn}
 has well-defined results.
+Then, any memory obtained is deallocated.
 \end{itemdescr}
 
 \rSec2[fpos]{Class template \tcode{fpos}}
@@ -4986,6 +4987,8 @@
 \returns
 The number of characters
 extracted by the last unformatted input member function called for the object.
+If the number cannot be represented,
+returns \tcode{numeric_limits<streamsize>::max()}.
 \end{itemdescr}
 
 \indexlibrarymember{get}{basic_istream}%
@@ -14217,6 +14220,11 @@
     bool operator==(const directory_entry& rhs) const noexcept;
     strong_ordering operator<=>(const directory_entry& rhs) const noexcept;
 
+    // \ref{fs.dir.entry.io}, inserter
+    template<class charT, class traits>
+      friend basic_ostream<charT, traits>&
+        operator<<(basic_ostream<charT, traits>& os, const directory_entry& d);
+
   private:
     filesystem::path pathobject;        // \expos
     friend class directory_iterator;    // \expos
@@ -14635,6 +14643,21 @@
 \tcode{pathobject <=> rhs.pathobject}.
 \end{itemdescr}
 
+\rSec3[fs.dir.entry.io]{Inserter}
+
+\indexlibrarymember{operator<<}{directory_entry}%
+\begin{itemdecl}
+template<class charT, class traits>
+  friend basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os, const directory_entry& d);
+\end{itemdecl}
+
+\begin{itemdescr}
+\pnum
+\effects
+Equivalent to: \tcode{return os << d.path();}
+\end{itemdescr}
+
 \rSec2[fs.class.directory.iterator]{Class \tcode{directory_iterator}}
 
 \rSec3[fs.class.directory.iterator.general]{General}
@@ -17184,39 +17207,39 @@
   imaxdiv_t div(intmax_t, intmax_t);    // optional, see below
 }
 
-#define PRIdN @\seebelow@
-#define PRIiN @\seebelow@
-#define PRIoN @\seebelow@
-#define PRIuN @\seebelow@
-#define PRIxN @\seebelow@
-#define PRIXN @\seebelow@
-#define SCNdN @\seebelow@
-#define SCNiN @\seebelow@
-#define SCNoN @\seebelow@
-#define SCNuN @\seebelow@
-#define SCNxN @\seebelow@
-#define PRIdLEASTN @\seebelow@
-#define PRIiLEASTN @\seebelow@
-#define PRIoLEASTN @\seebelow@
-#define PRIuLEASTN @\seebelow@
-#define PRIxLEASTN @\seebelow@
-#define PRIXLEASTN @\seebelow@
-#define SCNdLEASTN @\seebelow@
-#define SCNiLEASTN @\seebelow@
-#define SCNoLEASTN @\seebelow@
-#define SCNuLEASTN @\seebelow@
-#define SCNxLEASTN @\seebelow@
-#define PRIdFASTN @\seebelow@
-#define PRIiFASTN @\seebelow@
-#define PRIoFASTN @\seebelow@
-#define PRIuFASTN @\seebelow@
-#define PRIxFASTN @\seebelow@
-#define PRIXFASTN @\seebelow@
-#define SCNdFASTN @\seebelow@
-#define SCNiFASTN @\seebelow@
-#define SCNoFASTN @\seebelow@
-#define SCNuFASTN @\seebelow@
-#define SCNxFASTN @\seebelow@
+#define PRId@\placeholdernc{N}@ @\seebelow@
+#define PRIi@\placeholdernc{N}@ @\seebelow@
+#define PRIo@\placeholdernc{N}@ @\seebelow@
+#define PRIu@\placeholdernc{N}@ @\seebelow@
+#define PRIx@\placeholdernc{N}@ @\seebelow@
+#define PRIX@\placeholdernc{N}@ @\seebelow@
+#define SCNd@\placeholdernc{N}@ @\seebelow@
+#define SCNi@\placeholdernc{N}@ @\seebelow@
+#define SCNo@\placeholdernc{N}@ @\seebelow@
+#define SCNu@\placeholdernc{N}@ @\seebelow@
+#define SCNx@\placeholdernc{N}@ @\seebelow@
+#define PRIdLEAST@\placeholdernc{N}@ @\seebelow@
+#define PRIiLEAST@\placeholdernc{N}@ @\seebelow@
+#define PRIoLEAST@\placeholdernc{N}@ @\seebelow@
+#define PRIuLEAST@\placeholdernc{N}@ @\seebelow@
+#define PRIxLEAST@\placeholdernc{N}@ @\seebelow@
+#define PRIXLEAST@\placeholdernc{N}@ @\seebelow@
+#define SCNdLEAST@\placeholdernc{N}@ @\seebelow@
+#define SCNiLEAST@\placeholdernc{N}@ @\seebelow@
+#define SCNoLEAST@\placeholdernc{N}@ @\seebelow@
+#define SCNuLEAST@\placeholdernc{N}@ @\seebelow@
+#define SCNxLEAST@\placeholdernc{N}@ @\seebelow@
+#define PRIdFAST@\placeholdernc{N}@ @\seebelow@
+#define PRIiFAST@\placeholdernc{N}@ @\seebelow@
+#define PRIoFAST@\placeholdernc{N}@ @\seebelow@
+#define PRIuFAST@\placeholdernc{N}@ @\seebelow@
+#define PRIxFAST@\placeholdernc{N}@ @\seebelow@
+#define PRIXFAST@\placeholdernc{N}@ @\seebelow@
+#define SCNdFAST@\placeholdernc{N}@ @\seebelow@
+#define SCNiFAST@\placeholdernc{N}@ @\seebelow@
+#define SCNoFAST@\placeholdernc{N}@ @\seebelow@
+#define SCNuFAST@\placeholdernc{N}@ @\seebelow@
+#define SCNxFAST@\placeholdernc{N}@ @\seebelow@
 #define PRIdMAX @\seebelow@
 #define PRIiMAX @\seebelow@
 #define PRIoMAX @\seebelow@
@@ -17262,3 +17285,12 @@
 \end{itemize}
 
 \xrefc{7.8}
+
+\pnum
+Each of the \tcode{PRI} macros listed in this subclause
+is defined if and only if the implementation
+defines the corresponding typedef name in~\ref{cstdint.syn}.
+Each of the \tcode{SCN} macros listed in this subclause
+is defined if and only if the implementation
+defines the corresponding typedef name in~\ref{cstdint.syn} and
+has a suitable \tcode{fscanf} length modifier for the type.