P1690R1 Refinement Proposal for P0919 Heterogeneous lookup for unordered containers

Also fixes NB US 235, US 236, US 238, and PL 237 (C++20 CD).

Author: zygoloid

source/containers.tex

@@ -2320,8 +2320,10 @@
 \item \tcode{a_eq} denotes a value of type \tcode{X}
   when \tcode{X} supports equivalent keys,
 \item \tcode{a_tran} denotes a possibly const value of type \tcode{X}
-  when the \grammarterm{qualified-id} \tcode{X::hasher::transparent_key_equal}
-  is valid and denotes a type\iref{temp.deduct},
+  when the \grammarterm{qualified-id}s
+  \tcode{X::key_equal::is_transparent} and
+  \tcode{X::hasher::is_transparent}
+  are both valid and denote types\iref{temp.deduct},
 \item \tcode{i} and \tcode{j} denote input iterators
   that refer to \tcode{value_type},
 \item \tcode{[i, j)} denotes a valid range,
@@ -2402,9 +2404,7 @@
 %
 \indexunordmem{key_equal}%
 \tcode{X::key_equal}
-&   \tcode{Hash::transparent_key_equal} if such a \grammarterm{qualified-id}
-    is valid and denotes a type\iref{temp.deduct};
-    otherwise, \tcode{Pred}.
+&   \tcode{Pred}
 &   \expects \tcode{Pred} meets the \oldconcept{CopyConstructible} requirements.\br
     \tcode{Pred} is a binary predicate that takes two arguments
     of type \tcode{Key}.  \tcode{Pred} is an equivalence relation.%
@@ -3036,22 +3036,13 @@
 element is successfully inserted.
 
 \pnum
-If the \grammarterm{qualified-id} \tcode{Hash::transparent_key_equal}
-is valid and denotes a type\iref{temp.deduct},
-then the program is ill-formed if either:
-\begin{itemize}
-\item
-  \grammarterm{qualified-id} \tcode{Hash::transparent_key_equal::is_transparent}
-  is not valid or does not denote a type, or
-\item
-  \tcode{Pred} is a different type than \tcode{equal_to<Key>} or
-  \tcode{Hash::transparent_key_equal}.
-\end{itemize}
 The member function templates
 \tcode{find}, \tcode{count}, \tcode{equal_range}, and \tcode{contains}
 shall not participate in overload resolution unless
-the \grammarterm{qualified-id} \tcode{Hash::transparent_key_equal}
-is valid and denotes a type\iref{temp.deduct}.
+the \grammarterm{qualified-id}s
+\tcode{Pred::is_transparent} and
+\tcode{Hash::is_transparent}
+are both valid and denote types\iref{temp.deduct}.
 
 \pnum
 A deduction guide for an unordered associative container shall not participate in overload resolution
@@ -7977,7 +7968,7 @@
     using mapped_type          = T;
     using value_type           = pair<const Key, T>;
     using hasher               = Hash;
-    using key_equal            = @\seeref{unord.req}@;
+    using key_equal            = Pred;
     using allocator_type       = Allocator;
     using pointer              = typename allocator_traits<Allocator>::pointer;
     using const_pointer        = typename allocator_traits<Allocator>::const_pointer;
@@ -8576,7 +8567,7 @@
     using mapped_type          = T;
     using value_type           = pair<const Key, T>;
     using hasher               = Hash;
-    using key_equal            = @\seeref{unord.req}@;
+    using key_equal            = Pred;
     using allocator_type       = Allocator;
     using pointer              = typename allocator_traits<Allocator>::pointer;
     using const_pointer        = typename allocator_traits<Allocator>::const_pointer;
@@ -8945,7 +8936,7 @@
     using key_type             = Key;
     using value_type           = Key;
     using hasher               = Hash;
-    using key_equal            = @\seeref{unord.req}@;
+    using key_equal            = Pred;
     using allocator_type       = Allocator;
     using pointer              = typename allocator_traits<Allocator>::pointer;
     using const_pointer        = typename allocator_traits<Allocator>::const_pointer;
@@ -9274,7 +9265,7 @@
     using key_type             = Key;
     using value_type           = Key;
     using hasher               = Hash;
-    using key_equal            = @\seeref{unord.req}@;
+    using key_equal            = Pred;
     using allocator_type       = Allocator;
     using pointer              = typename allocator_traits<Allocator>::pointer;
     using const_pointer        = typename allocator_traits<Allocator>::const_pointer;

source/macros.tex

@@ -328,8 +328,6 @@
 \newcommand{\unspecbool}{\UNSP{unspecified-bool-type}}
 \newcommand{\seebelow}{\UNSP{see below}}
 \newcommand{\seebelownc}{\UNSPnc{see below}}
-\newcommand{\seeref}[1]{\UNSP{see~\ref{#1}}}
-\newcommand{\seerefnc}[1]{\UNSPnc{see~\ref{#1}}}
 \newcommand{\unspecuniqtype}{\UNSP{unspecified unique type}}
 \newcommand{\unspecalloctype}{\UNSP{unspecified allocator type}}