More fixes.

include/pqxx/cursor.hxx

@@ -448,7 +448,7 @@ public:
     return &m_here;
   }
   icursor_iterator &operator++();
-  icursor_iterator operator++(int);
+  icursor_iterator operator++(int) &;
   icursor_iterator &operator+=(difference_type);
   icursor_iterator &operator=(icursor_iterator const &) noexcept;
 

include/pqxx/internal/result_iterator.hxx

@@ -105,13 +105,13 @@ public:
     return *this;
   }
 
-  const_result_iterator operator++(int);
+  const_result_iterator operator++(int) &;
   const_result_iterator &operator++()
   {
     ++m_index;
     return *this;
   }
-  const_result_iterator operator--(int);
+  const_result_iterator operator--(int) &;
   const_result_iterator &operator--()
   {
     --m_index;
@@ -264,13 +264,13 @@ public:
     iterator_type::operator--();
     return *this;
   }
-  const_reverse_result_iterator operator++(int);
+  const_reverse_result_iterator operator++(int) &;
   const_reverse_result_iterator &operator--()
   {
     iterator_type::operator++();
     return *this;
   }
-  const_reverse_result_iterator operator--(int);
+  const_reverse_result_iterator operator--(int) &;
   const_reverse_result_iterator &operator+=(difference_type i)
   {
     iterator_type::operator-=(i);

include/pqxx/row.hxx

@@ -314,13 +314,13 @@ public:
   const_row_iterator &operator=(const_row_iterator const &) noexcept = default;
   const_row_iterator &operator=(const_row_iterator &&) noexcept = default;
 
-  const_row_iterator operator++(int) noexcept;
+  const_row_iterator operator++(int) & noexcept;
   const_row_iterator &operator++() noexcept
   {
     ++m_col;
     return *this;
   }
-  const_row_iterator operator--(int) noexcept;
+  const_row_iterator operator--(int) & noexcept;
   const_row_iterator &operator--() noexcept
   {
     --m_col;
@@ -441,13 +441,13 @@ public:
     iterator_type::operator--();
     return *this;
   }
-  const_reverse_row_iterator operator++(int) noexcept;
+  const_reverse_row_iterator operator++(int) & noexcept;
   const_reverse_row_iterator &operator--() noexcept
   {
     iterator_type::operator++();
     return *this;
   }
-  const_reverse_row_iterator operator--(int);
+  const_reverse_row_iterator operator--(int) &;
   const_reverse_row_iterator &operator+=(difference_type i) noexcept
   {
     iterator_type::operator-=(i);

src/connection.cxx

@@ -477,6 +477,7 @@ void wrap_pgfreecancel(PGcancel *ptr)
 }
 
 
+/// A fairly arbitrary buffer size for error strings and such.
 constexpr int buf_size{500u};
 } // namespace
 
@@ -489,7 +490,7 @@ void PQXX_COLD pqxx::connection::cancel_query()
     PQXX_UNLIKELY
   throw std::bad_alloc{};
 
-  std::array<char, buf_size> errbuf;
+  std::array<char, buf_size> errbuf{};
   auto const err{errbuf.data()};
   auto const c{PQcancel(cancel.get(), err, buf_size)};
   if (c == 0)
@@ -506,13 +507,13 @@ void pqxx::connection::set_blocking(bool block) &
   unsigned long mode{not block};
   if (::ioctlsocket(fd, FIONBIO, &mode) != 0)
   {
-    std::array<char, buf_size> errbuf;
+    std::array<char, buf_size> errbuf{};
     char const *err{pqxx::internal::error_string(WSAGetLastError(), errbuf)};
     throw broken_connection{
       internal::concat("Could not set socket's blocking mode: ", err)};
   }
 #  else  // _WIN32
-  std::array<char, buf_size> errbuf;
+  std::array<char, buf_size> errbuf{};
   auto flags{::fcntl(fd, F_GETFL, 0)};
   if (flags == -1)
   {

src/cursor.cxx

@@ -224,9 +224,9 @@ pqxx::icursor_iterator::~icursor_iterator() noexcept
 }
 
 
-pqxx::icursor_iterator pqxx::icursor_iterator::operator++(int)
+pqxx::icursor_iterator pqxx::icursor_iterator::operator++(int) &
 {
-  icursor_iterator old{*this};
+  icursor_iterator const old{*this};
   m_pos = difference_type(
     pqxx::internal::gate::icursorstream_icursor_iterator{*m_stream}.forward());
   m_here.clear();

src/params.cxx

@@ -80,15 +80,15 @@ void pqxx::params::append(std::basic_string<std::byte> &&value) &
 
 void PQXX_COLD pqxx::params::append(binarystring const &value) &
 {
-  m_params.push_back(entry{value.bytes_view()});
+  m_params.emplace_back(value.bytes_view());
 }
 
 
 void pqxx::params::append(params &&value) &
 {
   this->reserve(std::size(value.m_params) + std::size(this->m_params));
   for (auto const &param : value.m_params)
-    m_params.emplace_back(std::move(param));
+    m_params.emplace_back(param);
   value.m_params.clear();
 }
 

src/pipeline.cxx

@@ -25,11 +25,15 @@
 #include "pqxx/internal/header-post.hxx"
 
 
+using namespace std::literals::string_view_literals;
+
+
 namespace
 {
-std::string const theSeparator{"; "};
-std::string const theDummyValue{"1"};
-std::string const theDummyQuery{"SELECT " + theDummyValue + theSeparator};
+constexpr std::string_view
+    theSeparator{"; "sv},
+    theDummyValue{"1"sv},
+    theDummyQuery{"SELECT 1; "sv};
 } // namespace
 
 
@@ -209,7 +213,7 @@ void pqxx::pipeline::issue()
     QueryMap::size_type(std::distance(oldest, std::end(m_queries)))};
   bool const prepend_dummy{num_issued > 1};
   if (prepend_dummy)
-    cum = theDummyQuery + cum;
+    cum = pqxx::internal::concat(theDummyQuery, cum);
 
   pqxx::internal::gate::connection_pipeline{m_trans->conn()}.start_exec(
     cum.c_str());
@@ -300,7 +304,7 @@ void pqxx::pipeline::obtain_dummy()
       PQXX_UNLIKELY
     internal_error("Unexpected result for dummy query in pipeline.");
 
-    if (R.at(0).at(0).as<std::string>() != theDummyValue)
+    if (R.at(0).at(0).as<std::string_view>() != theDummyValue)
       PQXX_UNLIKELY
     internal_error("Dummy query in pipeline returned unexpected value.");
     return;

src/result.cxx

@@ -319,8 +319,6 @@ std::string pqxx::result::status_error() const
   case PGRES_EMPTY_QUERY: // The string sent to the backend was empty.
   case PGRES_COMMAND_OK:  // Successful completion, no result data.
   case PGRES_TUPLES_OK:   // The query successfully executed.
-    break;
-
   case PGRES_COPY_OUT:  // Copy Out (from server) data transfer started.
   case PGRES_COPY_IN:   // Copy In (to server) data transfer started.
   case PGRES_COPY_BOTH: // Copy In/Out.  Used for streaming replication.
@@ -524,17 +522,17 @@ int pqxx::result::column_type_modifier(
 
 // const_result_iterator
 
-pqxx::const_result_iterator pqxx::const_result_iterator::operator++(int)
+pqxx::const_result_iterator pqxx::const_result_iterator::operator++(int) &
 {
-  const_result_iterator old{*this};
+  const_result_iterator const old{*this};
   m_index++;
   return old;
 }
 
 
-pqxx::const_result_iterator pqxx::const_result_iterator::operator--(int)
+pqxx::const_result_iterator pqxx::const_result_iterator::operator--(int) &
 {
-  const_result_iterator old{*this};
+  const_result_iterator const old{*this};
   m_index--;
   return old;
 }
@@ -549,18 +547,18 @@ pqxx::result::const_reverse_iterator::base() const noexcept
 
 
 pqxx::const_reverse_result_iterator
-pqxx::const_reverse_result_iterator::operator++(int)
+pqxx::const_reverse_result_iterator::operator++(int) &
 {
-  const_reverse_result_iterator tmp{*this};
+  const_reverse_result_iterator const tmp{*this};
   iterator_type::operator--();
   return tmp;
 }
 
 
 pqxx::const_reverse_result_iterator
-pqxx::const_reverse_result_iterator::operator--(int)
+pqxx::const_reverse_result_iterator::operator--(int) &
 {
-  const_reverse_result_iterator tmp{*this};
+  const_reverse_result_iterator const tmp{*this};
   iterator_type::operator++();
   return tmp;
 }

src/row.cxx

@@ -208,15 +208,15 @@ bool PQXX_COLD pqxx::row::empty() const noexcept
 }
 
 
-pqxx::const_row_iterator pqxx::const_row_iterator::operator++(int) noexcept
+pqxx::const_row_iterator pqxx::const_row_iterator::operator++(int) & noexcept
 {
   auto const old{*this};
   m_col++;
   return old;
 }
 
 
-pqxx::const_row_iterator pqxx::const_row_iterator::operator--(int) noexcept
+pqxx::const_row_iterator pqxx::const_row_iterator::operator--(int) & noexcept
 {
   auto const old{*this};
   m_col--;
@@ -233,7 +233,7 @@ pqxx::const_reverse_row_iterator::base() const noexcept
 
 
 pqxx::const_reverse_row_iterator
-pqxx::const_reverse_row_iterator::operator++(int) noexcept
+pqxx::const_reverse_row_iterator::operator++(int) & noexcept
 {
   auto tmp{*this};
   operator++();
@@ -242,7 +242,7 @@ pqxx::const_reverse_row_iterator::operator++(int) noexcept
 
 
 pqxx::const_reverse_row_iterator
-pqxx::const_reverse_row_iterator::operator--(int)
+pqxx::const_reverse_row_iterator::operator--(int) &
 {
   auto tmp{*this};
   operator--();

src/stream_from.cxx

@@ -245,7 +245,7 @@ void pqxx::stream_from::parse_line()
         // Would love to emplace_back() here, but gcc 9.1 warns about the
         // constructor not throwing.  It suggests adding "noexcept."  Which
         // we can hardly do, without std::string_view guaranteeing it.
-        m_fields.push_back(zview{field_begin, write - field_begin});
+        m_fields.emplace_back(field_begin, write - field_begin);
         *write++ = '\0';
       }
       // Set up for the next field.
@@ -280,7 +280,7 @@ void pqxx::stream_from::parse_line()
   }
   else
   {
-    m_fields.push_back(zview{field_begin, write - field_begin});
+    m_fields.emplace_back(field_begin, write - field_begin);
     *write++ = '\0';
   }
 

src/stream_to.cxx

@@ -50,7 +50,8 @@ char escape_char(char special)
   }
   PQXX_UNLIKELY throw pqxx::internal_error{pqxx::internal::concat(
     "Stream escaping unexpectedly stopped at '",
-    static_cast<unsigned>(static_cast<unsigned char>(special)))};
+    static_cast<unsigned>(static_cast<unsigned char>(special)),
+    "'.")};
 }
 } // namespace
 

src/wait.cxx

@@ -128,7 +128,8 @@ void pqxx::internal::wait_fd(
 
   if (code == -1)
   {
-    std::array<char, 200> errbuf;
+    constexpr std::size_t buf_size{200u};
+    std::array<char, buf_size> errbuf{};
     int const err_code
     {
 #if defined(_WIN32) && (_WIN32_WINNT >= 0x0600)