Merge 2018-06 LWG Motion 25

Fixes #2142

Author: zygoloid

source/containers.tex

@@ -8979,8 +8979,9 @@
     Container c;
 
   public:
+    queue() : queue(Container()) {}
     explicit queue(const Container&);
-    explicit queue(Container&& = Container());
+    explicit queue(Container&&);
     template<class Alloc> explicit queue(const Alloc&);
     template<class Alloc> queue(const Container&, const Alloc&);
     template<class Alloc> queue(Container&&, const Alloc&);
@@ -9030,7 +9031,7 @@
 \end{itemdescr}
 
 \begin{itemdecl}
-explicit queue(Container&& cont = Container());
+explicit queue(Container&& cont);
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -9228,8 +9229,10 @@
     Compare comp;
 
   public:
+    priority_queue() : priority_queue(Compare()) {}
+    explicit priority_queue(const Compare& x) : priority_queue(x, Container()) {}
     priority_queue(const Compare& x, const Container&);
-    explicit priority_queue(const Compare& x = Compare(), Container&& = Container());
+    priority_queue(const Compare& x, Container&&);
     template<class InputIterator>
       priority_queue(InputIterator first, InputIterator last, const Compare& x,
                      const Container&);
@@ -9286,7 +9289,7 @@
 \indexlibrary{\idxcode{priority_queue}!constructor}%
 \begin{itemdecl}
 priority_queue(const Compare& x, const Container& y);
-explicit priority_queue(const Compare& x = Compare(), Container&& y = Container());
+priority_queue(const Compare& x, Container&& y);
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -9524,8 +9527,9 @@
     Container c;
 
   public:
+    stack() : stack(Container()) {}
     explicit stack(const Container&);
-    explicit stack(Container&& = Container());
+    explicit stack(Container&&);
     template<class Alloc> explicit stack(const Alloc&);
     template<class Alloc> stack(const Container&, const Alloc&);
     template<class Alloc> stack(Container&&, const Alloc&);
@@ -9572,7 +9576,7 @@
 
 \indexlibrary{\idxcode{stack}!constructor}%
 \begin{itemdecl}
-explicit stack(Container&& cont = Container());
+explicit stack(Container&& cont);
 \end{itemdecl}
 
 \begin{itemdescr}

source/future.tex

@@ -377,7 +377,8 @@
 namespace std {
   class strstreambuf : public basic_streambuf<char> {
   public:
-    explicit strstreambuf(streamsize alsize_arg = 0);
+    strstreambuf() : strstreambuf(0) {}
+    explicit strstreambuf(streamsize alsize_arg);
     strstreambuf(void* (*palloc_arg)(size_t), void (*pfree_arg)(void*));
     strstreambuf(char* gnext_arg, streamsize n, char* pbeg_arg = nullptr);
     strstreambuf(const char* gnext_arg, streamsize n);
@@ -486,7 +487,7 @@
 
 \indexlibrary{\idxcode{strstreambuf}!constructor}%
 \begin{itemdecl}
-explicit strstreambuf(streamsize alsize_arg = 0);
+explicit strstreambuf(streamsize alsize_arg);
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -2798,7 +2799,8 @@
       using state_type  = typename Codecvt::state_type;
       using int_type    = typename wide_string::traits_type::int_type;
 
-      explicit wstring_convert(Codecvt* pcvt = new Codecvt);
+      wstring_convert() : wstring_convert(new Codecvt) {}
+      explicit wstring_convert(Codecvt* pcvt);
       wstring_convert(Codecvt* pcvt, state_type state);
       explicit wstring_convert(const byte_string& byte_err,
                                const wide_string& wide_err = wide_string());
@@ -2992,7 +2994,7 @@
 
 \indexlibrary{\idxcode{wstring_convert}!constructor}%
 \begin{itemdecl}
-explicit wstring_convert(Codecvt* pcvt = new Codecvt);
+explicit wstring_convert(Codecvt* pcvt);
 wstring_convert(Codecvt* pcvt, state_type state);
 explicit wstring_convert(const byte_string& byte_err,
     const wide_string& wide_err = wide_string());
@@ -3046,7 +3048,8 @@
     public:
       using state_type = typename Codecvt::state_type;
 
-      explicit wbuffer_convert(streambuf* bytebuf = nullptr,
+      wbuffer_convert() : wbuffer_convert(nullptr) {}
+      explicit wbuffer_convert(streambuf* bytebuf,
                                Codecvt* pcvt = new Codecvt,
                                state_type state = state_type());
 
@@ -3133,7 +3136,7 @@
 \indexlibrary{\idxcode{wbuffer_convert}!constructor}%
 \begin{itemdecl}
 explicit wbuffer_convert(
-    streambuf* bytebuf = nullptr,
+    streambuf* bytebuf,
     Codecvt* pcvt = new Codecvt,
     state_type state = state_type());
 \end{itemdecl}

source/iostreams.tex

@@ -7371,8 +7371,8 @@
     using allocator_type = Allocator;
 
     // \ref{stringbuf.cons}, constructors
-    explicit basic_stringbuf(
-      ios_base::openmode which = ios_base::in | ios_base::out);
+    basic_stringbuf() : basic_stringbuf(ios_base::in | ios_base::out) {}
+    explicit basic_stringbuf(ios_base::openmode which);
     explicit basic_stringbuf(
       const basic_string<charT, traits, Allocator>& str,
       ios_base::openmode which = ios_base::in | ios_base::out);
@@ -7439,8 +7439,7 @@
 
 \indexlibrary{\idxcode{basic_stringbuf}!constructor}%
 \begin{itemdecl}
-explicit basic_stringbuf(
-  ios_base::openmode which = ios_base::in | ios_base::out);
+explicit basic_stringbuf(ios_base::openmode which);
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -7891,8 +7890,8 @@
     using allocator_type = Allocator;
 
     // \ref{istringstream.cons}, constructors
-    explicit basic_istringstream(
-      ios_base::openmode which = ios_base::in);
+    basic_istringstream() : basic_istringstream(ios_base::in) {}
+    explicit basic_istringstream(ios_base::openmode which);
     explicit basic_istringstream(
       const basic_string<charT, traits, Allocator>& str,
       ios_base::openmode which = ios_base::in);
@@ -7937,7 +7936,7 @@
 
 \indexlibrary{\idxcode{basic_istringstream}!constructor}%
 \begin{itemdecl}
-explicit basic_istringstream(ios_base::openmode which = ios_base::in);
+explicit basic_istringstream(ios_base::openmode which);
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -8078,8 +8077,8 @@
     using allocator_type = Allocator;
 
     // \ref{ostringstream.cons}, constructors
-    explicit basic_ostringstream(
-      ios_base::openmode which = ios_base::out);
+    basic_ostringstream() : basic_ostringstream(ios_base::out) {}
+    explicit basic_ostringstream(ios_base::openmode which);
     explicit basic_ostringstream(
       const basic_string<charT, traits, Allocator>& str,
       ios_base::openmode which = ios_base::out);
@@ -8124,8 +8123,7 @@
 
 \indexlibrary{\idxcode{basic_ostringstream}!constructor}%
 \begin{itemdecl}
-explicit basic_ostringstream(
-  ios_base::openmode which = ios_base::out);
+explicit basic_ostringstream(ios_base::openmode which);
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -8266,8 +8264,8 @@
     using allocator_type = Allocator;
 
     // \ref{stringstream.cons}, constructors
-    explicit basic_stringstream(
-      ios_base::openmode which = ios_base::out | ios_base::in);
+    basic_stringstream() : basic_stringstream(ios_base::out | ios_base::in) {}
+    explicit basic_stringstream(ios_base::openmode which);
     explicit basic_stringstream(
       const basic_string<charT, traits, Allocator>& str,
       ios_base::openmode which = ios_base::out | ios_base::in);
@@ -8313,8 +8311,7 @@
 
 \indexlibrary{\idxcode{basic_stringstream}!constructor}%
 \begin{itemdecl}
-explicit basic_stringstream(
-  ios_base::openmode which = ios_base::out | ios_base::in);
+explicit basic_stringstream(ios_base::openmode which);
 \end{itemdecl}
 
 \begin{itemdescr}