LWG3595 Exposition-only classes proxy and postfix-proxy for common_iterator should be fully constexpr

Author: jensmaurer

source/iterators.tex

@@ -4959,10 +4959,10 @@
 \begin{codeblock}
 class @\exposid{proxy}@ {
   iter_value_t<I> keep_;
-  @\exposid{proxy}@(iter_reference_t<I>&& x)
+  constexpr @\exposid{proxy}@(iter_reference_t<I>&& x)
     : keep_(std::move(x)) {}
 public:
-  const iter_value_t<I>* operator->() const {
+  constexpr const iter_value_t<I>* operator->() const noexcept {
     return addressof(keep_);
   }
 };
@@ -5028,10 +5028,10 @@
 \begin{codeblock}
 class @\exposid{postfix-proxy}@ {
   iter_value_t<I> keep_;
-  @\exposid{postfix-proxy}@(iter_reference_t<I>&& x)
+  constexpr @\exposid{postfix-proxy}@(iter_reference_t<I>&& x)
     : keep_(std::forward<iter_reference_t<I>>(x)) {}
 public:
-  const iter_value_t<I>& operator*() const {
+  constexpr const iter_value_t<I>& operator*() const noexcept {
     return keep_;
   }
 };