c++ - Why isn't std::find() using my operator==? -

In the following snippet, I have overloaded the comparison of my pair of operator == string

Type in with but for some reason, the compiler is not searching for my operator as a match for the search function. why not?

Edit: Thanks for all the suggestions for the options, but I still want to understand why . This code looks like it should work; I want to know why this does not happen.

  #include & lt; Vector & gt; # Include & lt; Utility & gt; #include & lt; String & gt; # Include & lt; Algorithm & gt; Typedef std :: pair & lt; Std :: string, int & gt; RegPair; Typedef std :: vector & lt; RegPair & gt; RegPairSeq; Bull Operator == (Const Repechier & LHS, Constant Strode :: String & amp; rhs) {Return lhs.first == rhs; } Int main () {RegPairSeq sequence; Std :: string foo ("foo"); // stuff that is not important std :: find (sequence.begin (), sequence.end (), foo); // g ++: Error: 'operator ==' has no match for '__first' in __gnu_cxx :: __ normal_iterator & LT; _Iterator, _Container & gt; :: operator * [_Iterator = std :: pair & lt; Std :: basic_string & lt; Four, std :: char_traits & lt; Four>, std :: defluent & lt; Four & gt; & Gt;, integer & gt; *, _Container = std :: vector & lt; Std :: pair & lt; Std :: basic_string & lt; Four, std :: char_traits & lt; Four>, std :: defluent & lt; Four & gt; & Gt; Integer & gt ;, std :: communicator & lt; Std :: pair & lt; Std :: basic_string & lt; Four, std :: char_traits & lt; Four>, std :: defluent & lt; Four & gt; & Gt ;, int & gt; & Gt; & Gt;] () == __val '// Playing ++: Error: invalid operands to binary expression (' std :: pair & lt; std :: basic_string & lt; four & gt ;, integer & gt; ' And 'std :: basic_string & lt; four & gt; constants')}    
 
 
 The problem is that  std :: find  is a function template and it seems right to use logic dependent view (ADL) to use  operator == .  
 Both the code of the argument  in the code> name space ( std :: pair & lt; std :: string, int & gt;  and  Std :: string ), hence ADL  std  name space in it some  operator ==  (that does not matter, no matter what, in the standard library a lot Are all and if you have included  & lt; string & gt;  at least that can compare two  std :: basic_string & lt; T & gt;  items is).  
 Because a  operator ==  is found in overload  std  namespace, ADL prevents the detection of scops being closed. Your surcharge, which is located in the global name space, has never been found. Name lookup before the overload resolution; It does not make any difference in the name of the logic.