LWG3766 view_interface::cbegin is underconstrained

burblebee · tkoeppe · commit abe694703426 · 2022-12-15T14:34:28.000Z
diff --git a/source/ranges.tex b/source/ranges.tex
@@ -1696,16 +1696,16 @@
         return ranges::begin(@\exposid{derived}@()) == ranges::end(@\exposid{derived}@());
     }
 
-    constexpr auto cbegin() {
+    constexpr auto cbegin() requires @\libconcept{input_range}@<D> {
       return ranges::cbegin(@\exposid{derived}@());
     }
-    constexpr auto cbegin() const requires @\libconcept{range}@<const D> {
+    constexpr auto cbegin() const requires @\libconcept{input_range}@<const D> {
       return ranges::cbegin(@\exposid{derived}@());
     }
-    constexpr auto cend() {
+    constexpr auto cend() requires @\libconcept{input_range}@<D> {
       return ranges::cend(@\exposid{derived}@());
     }
-    constexpr auto cend() const requires @\libconcept{range}@<const D> {
+    constexpr auto cend() const requires @\libconcept{input_range}@<const D> {
       return ranges::cend(@\exposid{derived}@());
     }
 

Original file line number	Diff line number	Diff line change
`@@ -1696,16 +1696,16 @@`
`1696`	`1696`	`return ranges::begin(@\exposid{derived}@()) == ranges::end(@\exposid{derived}@());`
`1697`	`1697`	`}`
`1698`	`1698`
`1699`		`- constexpr auto cbegin() {`
	`1699`	`+ constexpr auto cbegin() requires @\libconcept{input_range}@<D> {`
`1700`	`1700`	`return ranges::cbegin(@\exposid{derived}@());`
`1701`	`1701`	`}`
`1702`		`- constexpr auto cbegin() const requires @\libconcept{range}@<const D> {`
	`1702`	`+ constexpr auto cbegin() const requires @\libconcept{input_range}@<const D> {`
`1703`	`1703`	`return ranges::cbegin(@\exposid{derived}@());`
`1704`	`1704`	`}`
`1705`		`- constexpr auto cend() {`
	`1705`	`+ constexpr auto cend() requires @\libconcept{input_range}@<D> {`
`1706`	`1706`	`return ranges::cend(@\exposid{derived}@());`
`1707`	`1707`	`}`
`1708`		`- constexpr auto cend() const requires @\libconcept{range}@<const D> {`
	`1708`	`+ constexpr auto cend() const requires @\libconcept{input_range}@<const D> {`
`1709`	`1709`	`return ranges::cend(@\exposid{derived}@());`
`1710`	`1710`	`}`
`1711`	`1711`