LWG3843 std::expected<T,E>::value() & assumes E is copy constructible

Author: burblebee

source/utilities.tex

@@ -8169,13 +8169,17 @@
 \end{itemdecl}
 
 \begin{itemdescr}
+\pnum
+\mandates
+\tcode{is_copy_constructible_v<E>} is \tcode{true}.
+
 \pnum
 \returns
 \exposid{val}, if \tcode{has_value()} is \tcode{true}.
 
 \pnum
 \throws
-\tcode{bad_expected_access(error())} if \tcode{has_value()} is \tcode{false}.
+\tcode{bad_expected_access(as_const(error()))} if \tcode{has_value()} is \tcode{false}.
 \end{itemdescr}
 
 \indexlibrarymember{value}{expected}%
@@ -8185,6 +8189,11 @@
 \end{itemdecl}
 
 \begin{itemdescr}
+\pnum
+\mandates
+\tcode{is_copy_constructible_v<E>} is \tcode{true} and
+\tcode{is_constructible_v<E, decltype(std::\linebreak{}move(error()))>} is \tcode{true}.
+
 \pnum
 \returns
 \tcode{std::move(\exposid{val})}, if \tcode{has_value()} is \tcode{true}.