Clear error codes idiomatically

example/common/detect_ssl.hpp

@@ -154,7 +154,7 @@ detect_ssl(
         {
             // This is a fast way to indicate success
             // without retrieving the default category.
-            ec.assign(0, ec.category());
+            ec = {};
             return result;
         }
 

example/doc/http_examples.hpp

@@ -1094,7 +1094,7 @@ read_and_print_body(
         p.get().body().size = sizeof(buf);
         read(stream, buffer, p, ec);
         if(ec == error::need_buffer)
-            ec.assign(0, ec.category());
+            ec = {};
         if(ec)
             return;
         os.write(buf, sizeof(buf) - p.get().body().size);
@@ -1201,7 +1201,7 @@ print_chunked_body(
         else if(ec != error::end_of_chunk)
             return;
         else
-            ec.assign(0, ec.category());
+            ec = {};
 
         // We got a whole chunk, print the extensions:
         for(auto const& extension : ce)

example/http/client/async-ssl/http_client_async_ssl.cpp

@@ -191,7 +191,7 @@ public:
         {
             // Rationale:
             // http://stackoverflow.com/questions/25587403/boost-asio-ssl-async-shutdown-always-finishes-with-an-error
-            ec.assign(0, ec.category());
+            ec = {};
         }
         if(ec)
             return fail(ec, "shutdown");

example/http/client/coro-ssl/http_client_coro_ssl.cpp

@@ -113,7 +113,7 @@ do_session(
     {
         // Rationale:
         // http://stackoverflow.com/questions/25587403/boost-asio-ssl-async-shutdown-always-finishes-with-an-error
-        ec.assign(0, ec.category());
+        ec = {};
     }
     if(ec)
         return fail(ec, "shutdown");

example/http/client/sync-ssl/http_client_sync_ssl.cpp

@@ -111,7 +111,7 @@ int main(int argc, char** argv)
         {
             // Rationale:
             // http://stackoverflow.com/questions/25587403/boost-asio-ssl-async-shutdown-always-finishes-with-an-error
-            ec.assign(0, ec.category());
+            ec = {};
         }
         if(ec)
             throw beast::system_error{ec};