[boost] Boost.Operators and make_shared

Subject: [boost] Boost.Operators and make_shared
From: Pieter (PieterB_at_[hidden])
Date: 2013-07-12 04:41:09

LS,

 

I have noticed that using Boost.Operators has a side-effect which I can't
explain. I am using std::make_shared as a default, however, some of the
boost libraries I use pull in boost::make_shared as well.

When using some class T2 derived from one of the boost.operators classes,
this causes MSVC2010 to  not compile when invoking make_shared<T2> as the
compiler can no longer resolve between the two overloaded versions of
make_shared for some reason.

 

I am hoping that someone out can explain what is happening here. A minimal
example is included here:

 

#include <memory>

#include <boost\operators.hpp>

#include <boost\make_shared.hpp>

 

struct T1 {};

struct T2 : boost::equality_comparable<T2> {};

 

int main( int argc, const char* argv[] )

{

   T1 Object1;

   T2 Object2;

 

   using std::make_shared;

   

   std::shared_ptr<T1> Ptr1 = make_shared<T1>(Object1); // OK

   std::shared_ptr<T2> Ptr2 = make_shared<T2>(Object2); // error C2668:
'boost::make_shared' : ambiguous call to overloaded function

 

   return 1;

}

 

Thanks in advance!

Pieter