LWG2583 There is no way to supply an allocator for basic_string(str, pos)

Author: Dawn Perchik

source/strings.tex

@@ -895,7 +895,9 @@
     explicit basic_string(const Allocator& a) noexcept;
     basic_string(const basic_string& str);
     basic_string(basic_string&& str) noexcept;
-    basic_string(const basic_string& str, size_type pos, size_type n = npos,
+    basic_string(const basic_string& str, size_type pos,
+                 const Allocator& a = Allocator());
+    basic_string(const basic_string& str, size_type pos, size_type n,
                  const Allocator& a = Allocator());
     basic_string(const charT* s,
                  size_type n, const Allocator& a = Allocator());
@@ -1181,8 +1183,7 @@
 
 \indexlibrary{\idxcode{basic_string}!constructor}%
 \begin{itemdecl}
-basic_string(const basic_string& str,
-             size_type pos, size_type n = npos,
+basic_string(const basic_string& str, size_type pos,
              const Allocator& a = Allocator());
 \end{itemdecl}
 
@@ -1198,12 +1199,31 @@
 Constructs an object of class
 \tcode{basic_string}
 and determines the effective length \tcode{rlen} of the initial string
-value as the smaller of \tcode{n} and
-\tcode{str.size() - pos},
+value as \tcode{str.size() - pos},
+as indicated in Table~\ref{tab:strings.ctr.2}.
+\end{itemdescr}
+
+\indexlibrary{\idxcode{basic_string}!constructor}%
+\begin{itemdecl}
+basic_string(const basic_string& str, size_type pos, size_type n,
+             const Allocator& a = Allocator());
+\end{itemdecl}
+
+\begin{itemdescr}
+\pnum
+\throws
+\tcode{out_of_range} if \tcode{pos > str.size()}.
+
+\pnum
+\effects
+Constructs an object of class \tcode{basic_string}
+and determines the effective length \tcode{rlen} of the initial string
+value as the smaller of \tcode{n} and \tcode{str.size() - pos},
 as indicated in Table~\ref{tab:strings.ctr.2}.
 
 \begin{libefftabvalue}
-{\tcode{basic_string(const basic_string\&, size_type, size_type, const Allocator\&)} effects}
+{\tcode{basic_string(const basic_string\&, size_type, const Allocator\&)}\protect\linebreak and
+\tcode{basic_string(const basic_string\&, size_type, size_type, const Allocator\&)} effects}
 {tab:strings.ctr.2}
 \tcode{data()}      &
 points at the first element of an allocated copy of \tcode{rlen} consecutive elements