[container.requirements] Simplify Returns specification for try_emplace (#7892)

Author: Eisenwave

source/containers.tex

@@ -3239,8 +3239,7 @@
 
 \pnum
 \returns
-An iterator pointing to the element
-with the key equivalent to the newly inserted element.
+The iterator returned by \tcode{emplace}.
 
 \pnum
 \complexity
@@ -4941,26 +4940,16 @@
 \result
 \tcode{iterator}
 
-\pnum
-\expects
-\tcode{value_type} is
-\oldconcept{EmplaceConstructible} into \tcode{X} from \tcode{args}.
-
 \pnum
 \effects
-Equivalent to \tcode{a.emplace(std::forward<Args>(args)...)}.
-
-\pnum
-\returns
-An iterator pointing to the element
-with the key equivalent to the newly inserted element.
-The \tcode{const_iterator} \tcode{p} is a hint
+Equivalent to \tcode{a.emplace(std::forward<Args>(args)...)},
+except that the \tcode{const_iterator} \tcode{p} is a hint
 pointing to where the search should start.
 Implementations are permitted to ignore the hint.
 
 \pnum
-\complexity
-Average case \bigoh{1}, worst case \bigoh{\tcode{a.size()}}.
+\returns
+The iterator returned by \tcode{emplace}.
 \end{itemdescr}
 
 \indexunordmem{insert}%