Problem: message_t::operator== is absurdly inefficient and constructs temporary copies of both operands

sigiesec · sigiesec · commit c92afb675e86 · 2018-04-13T11:28:40.000-04:00
Solution: implement operator== using memcmp instead
diff --git a/zmq.hpp b/zmq.hpp
@@ -393,11 +393,10 @@ namespace zmq
 
         inline bool operator==(const message_t &other) const ZMQ_NOTHROW
         {
+            size_t my_size = size ();
             if (size () != other.size ())
                 return false;
-            const std::string a(data<char>(), size());
-            const std::string b(other.data<char>(), other.size());
-            return a == b;
+            return 0 == memcmp (data (), other.data (), my_size);
         }
 
         inline bool operator!=(const message_t &other) const ZMQ_NOTHROW

Original file line number	Diff line number	Diff line change
`@@ -393,11 +393,10 @@ namespace zmq`
`393`	`393`
`394`	`394`	`inline bool operator==(const message_t &other) const ZMQ_NOTHROW`
`395`	`395`	`{`
	`396`	`+ size_t my_size = size ();`
`396`	`397`	`if (size () != other.size ())`
`397`	`398`	`return false;`
`398`		`- const std::string a(data<char>(), size());`
`399`		`- const std::string b(other.data<char>(), other.size());`
`400`		`- return a == b;`
	`399`	`+ return 0 == memcmp (data (), other.data (), my_size);`
`401`	`400`	`}`
`402`	`401`
`403`	`402`	`inline bool operator!=(const message_t &other) const ZMQ_NOTHROW`