LWG4533 not_fn<f> is unimplementable

burblebee · tkoeppe · commit b1fe7753e9b8 · 2026-04-18T01:09:56.000+01:00
diff --git a/source/utilities.tex b/source/utilities.tex
@@ -11788,19 +11788,20 @@
 A \defnadj{callable}{object} is an object of a callable type.
 
 \pnum
-A \defnx{call wrapper type}{call wrapper!type} is a type that holds a callable object
-and supports a call operation that forwards to that object.
+A \defnx{call wrapper type}{call wrapper!type} is a type that holds
+a \defnadj{target}{object},
+which is either
+a callable object or
+an object representing a callable object,
+and supports a call operation that forwards to that callable object.
 
 \pnum
 A \defn{call wrapper} is an object of a call wrapper type.
 
-\pnum
-A \defn{target object} is the callable object held by a call wrapper.
-
 \pnum
 A call wrapper type may additionally hold
 a sequence of objects and references
-that may be passed as arguments to the target object.
+that may be passed as arguments to the callable object.
 These entities are collectively referred to
 as \defnx{bound argument entities}{bound argument entity}.
 
@@ -13498,9 +13499,9 @@
 
 \pnum
 \returns
-A perfect forwarding call wrapper\iref{func.require} \tcode{g} that
-does not have state entities, and
-has the call pattern \tcode{!invoke(f, call_args...)}.
+A perfect forwarding call wrapper\iref{func.require} \tcode{g}
+whose target object is a copy of \tcode{cw<f>}, and
+whose call pattern is \tcode{!invoke(f, call_args...)}.
 \end{itemdescr}
 
 \rSec2[func.bind.partial]{Function templates \tcode{bind_front} and \tcode{bind_back}}
@@ -13620,8 +13621,9 @@
 
 \pnum
 \returns
-A perfect forwarding call wrapper\iref{func.require} \tcode{g} that
-does not have a target object, and has the call pattern:
+A perfect forwarding call wrapper\iref{func.require} \tcode{g}
+whose target object is a copy of \tcode{cw<f>}, and
+whose call pattern is:
 \begin{itemize}
 \item
 \tcode{invoke(f, bound_args..., call_args...)}
