Demo http://stackoverflow.com/questions/42983330/

a.cpp

#include "a.h"

#include <boost/asio/error.hpp>
#include <iostream>
#include <map>
#include <sstream>

namespace A  {

    std::string ErrorCodeToString(const boost::system::error_code & errorCode)
    {
        static const std::map<boost::system::error_code, std::string> my_own_descriptions {
            { boost::asio::error::eof, "Server has disconnected." },
            { boost::asio::error::connection_refused, "Connection Refused." },
        }; 

        auto& c = errorCode.category();
        std::cout << "Match get_misc_category(): " << (c == boost::asio::error::get_misc_category())
                  << " misc_category(): " << (c == boost::asio::error::misc_category) << "\n";

        std::ostringstream debugMsg;
        debugMsg << "Error Category: " << errorCode.category().name() << ". "
                 << "Error Message: "  << errorCode.message() << ". ";

        auto match = my_own_descriptions.find(errorCode);
        if (match != my_own_descriptions.end()) {
            debugMsg << "Server has disconnected.";
        }
        else {
            debugMsg << "Unknown Error.";
        }

        return debugMsg.str();
    }

}

a.h

#pragma once
#include <boost/system/error_code.hpp>
#include <string>

namespace A {
    std::string ErrorCodeToString(const boost::system::error_code & errorCode);
}

b.cpp

#include "b.h"
#include <boost/asio/error.hpp>

namespace B {
    boost::system::error_code foo() {
        return boost::asio::error::eof;
    }
}

b.h

#pragma once
#include <boost/system/error_code.hpp>

namespace B {
    boost::system::error_code foo();
}

c.cpp

#define BOOST_ERROR_CODE_HEADER_ONLY
#include <boost/asio/error.hpp>

// just to define the globals that would normally be in the dynamic library

CMakeLists.txt

SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} \
    -isystem /home/sehe/custom/boost \
    -std=c++11 \
    -g -O2 -pthread -march=native")

add_definitions("-DBOOST_SYSTEM_NO_LIB")

ADD_LIBRARY(a_a a.cpp)
ADD_LIBRARY(b_a b.cpp)
ADD_LIBRARY(c_a c.cpp)

ADD_EXECUTABLE(sotest test.cpp)

target_link_libraries(a_a c_a)
target_link_libraries(b_a c_a)
target_link_libraries(sotest a_a b_a)

test.cpp

#include "a.h" // one static library, static linked to boost system
#include "b.h" // another static library, static linked to boost system
#include <iostream>

int main() {
    std::cout << A::ErrorCodeToString(B::foo()) << "\n";
}