[expected.object.assign] Add missing 'Returns: *this'

Author: jensmaurer

source/utilities.tex

@@ -7760,6 +7760,10 @@
 Then, if no exception was thrown,
 equivalent to: \tcode{\exposid{has_val} = rhs.has_value(); return *this;}
 
+\pnum
+\returns
+\tcode{*this}.
+
 \pnum
 \remarks
 This operator is defined as deleted unless:
@@ -7822,6 +7826,10 @@
 Then, if no exception was thrown,
 equivalent to: \tcode{has_val = rhs.has_value(); return *this;}
 
+\pnum
+\returns
+\tcode{*this}.
+
 \pnum
 \remarks
 The exception specification is equivalent to: