I encountered a problem in my project when using Boost.Exception with the predefined types errinfo_xyz in a library project. I have two classes ClassA and ClassB in my library which both throw a boost::exception with errinfo_api_function type in their implementation file (.cpp) These both classes are compiled into a static library with the C/C++-Flags -fvisibility=hidden.

Then I have a main.cpp which creates an instance of ClassA and ClassB and links to the library which contains ClassA.o and ClassB.o. When I compile the main.cpp I get the linker error duplicate symbol for the errinfo_api_function object in ClassA.o and ClassB.o. If I remove the visibility=hidden flag, it links without problems. I am not an expert on the compiler flags, but I saw that many libraries use the visibility=hidden flag so I think it would be good, if my lib could also use it.   

For a better description I will show the sources for my project:

ClassA.h

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#pragma once

#include <boost/exception/all.hpp>

struct my_errorB : virtual std::exception, virtual boost::exception {};

class ClassB
{
public:
  ClassB() {};
  virtual ~ ClassB() {};

  virtual void doSomething();
};

main.cpp

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The Linker output:

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I hope I described the problem well enough and I hope someone can explain what the problem is? Thank a lot and

best regards

Georg