LWG3075 basic_string needs deduction guides from basic_string_view

Author: Dawn Perchik

source/strings.tex

@@ -1150,9 +1150,29 @@
       -> basic_string<typename iterator_traits<InputIterator>::value_type,
                       char_traits<typename iterator_traits<InputIterator>::value_type>,
                       Allocator>;
+
+  template<class charT,
+           class traits,
+           class Allocator = allocator<charT>>
+    explicit basic_string(basic_string_view<charT, traits>, const Allocator& = Allocator())
+      -> basic_string<charT, traits, Allocator>;
+  
+  template<class charT,
+           class traits,
+           class Allocator = allocator<charT>>
+    basic_string(basic_string_view<charT, traits>,
+                 typename @\seebelow@::size_type, typename @\seebelow@::size_type, 
+                 const Allocator& = Allocator())
+      -> basic_string<charT, traits, Allocator>;
 }
 \end{codeblock}
 
+\pnum
+A \tcode{size_type} parameter type in
+a \tcode{basic_string} deduction guide
+refers to the \tcode{size_type} member type of
+the type deduced by the deduction guide.
+
 \rSec3[string.require]{General requirements}
 
 \pnum
@@ -1458,6 +1478,29 @@
 or if \tcode{Allocator} is a type that does not qualify as an allocator\iref{container.requirements.general}.
 \end{itemdescr}
 
+\begin{itemdecl}
+template<class charT,
+         class traits,
+         class Allocator = allocator<charT>>
+  explicit basic_string(basic_string_view<charT, traits>, const Allocator& = Allocator())
+    -> basic_string<charT, traits, Allocator>;
+
+template<class charT,
+         class traits,
+         class Allocator = allocator<charT>>
+  basic_string(basic_string_view<charT, traits>,
+               typename @\seebelow@::size_type, typename @\seebelow@::size_type, 
+               const Allocator& = Allocator())
+    -> basic_string<charT, traits, Allocator>;
+\end{itemdecl}
+
+\begin{itemdescr}
+\pnum
+\remarks Shall not participate in overload resolution if
+\tcode{Allocator} is a type that does not qualify as
+an allocator\iref{container.requirements.general}.
+\end{itemdescr}
+
 \indexlibrarymember{operator=}{basic_string}%
 \begin{itemdecl}
 basic_string& operator=(const basic_string& str);