Fix some of the visibility issues

include/boost/test/impl/decorator.ipp

@@ -18,6 +18,7 @@
 // Boost.Test
 #include <boost/test/tree/decorator.hpp>
 #include <boost/test/tree/test_unit.hpp>
+#include <boost/test/impl/trivial_singleton.ipp>
 
 #include <boost/test/framework.hpp>
 #if BOOST_TEST_SUPPORT_TOKEN_ITERATOR

include/boost/test/impl/progress_monitor.ipp

@@ -17,6 +17,7 @@
 
 // Boost.Test
 #include <boost/test/progress_monitor.hpp>
+#include <boost/test/impl/trivial_singleton.ipp>
 #include <boost/test/unit_test_parameters.hpp>
 
 #include <boost/test/utils/setcolor.hpp>

include/boost/test/impl/results_collector.ipp

@@ -16,6 +16,7 @@
 // Boost.Test
 #include <boost/test/unit_test_log.hpp>
 #include <boost/test/results_collector.hpp>
+#include <boost/test/impl/trivial_singleton.ipp>
 #include <boost/test/framework.hpp>
 
 #include <boost/test/tree/test_unit.hpp>

include/boost/test/impl/test_framework_init_observer.ipp

@@ -14,6 +14,7 @@
 
 // Boost.Test
 #include <boost/test/test_framework_init_observer.hpp>
+#include <boost/test/impl/trivial_singleton.ipp>
 #include <boost/test/framework.hpp>
 #include <boost/test/detail/suppress_warnings.hpp>
 

include/boost/test/impl/trivial_singleton.ipp

@@ -0,0 +1,26 @@
+//  (C) Copyright Gennadiy Rozental 2001.
+//  (C) Antony Polukhin 2018.
+//  Distributed under the Boost Software License, Version 1.0.
+//  (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+
+// This header must be included ONLY in the *.ipp files to avoid issues with visibility.
+// See the long discussion starting
+// from https://github.com/boostorg/boost/pull/190#issuecomment-422197454
+
+#ifndef BOOST_TEST_IMPL_TRIVIAL_SIGNLETON_IPP
+#define BOOST_TEST_IMPL_TRIVIAL_SIGNLETON_IPP
+
+#include <boost/test/utils/trivial_singleton.hpp>
+
+namespace boost { namespace unit_test {
+
+template<typename Derived>
+Derived& singleton<Derived>::instance() {
+  static Derived the_inst;
+  return the_inst;
+}
+
+}}
+
+#endif // BOOST_TEST_IMPL_TRIVIAL_SIGNLETON_IPP

include/boost/test/impl/unit_test_log.ipp

@@ -19,6 +19,7 @@
 #include <boost/test/unit_test_log.hpp>
 #include <boost/test/unit_test_log_formatter.hpp>
 #include <boost/test/execution_monitor.hpp>
+#include <boost/test/impl/trivial_singleton.ipp>
 #include <boost/test/framework.hpp>
 #include <boost/test/unit_test_parameters.hpp>
 

include/boost/test/impl/unit_test_monitor.ipp

@@ -18,6 +18,7 @@
 
 // Boost.Test
 #include <boost/test/unit_test_monitor.hpp>
+#include <boost/test/impl/trivial_singleton.ipp>
 #include <boost/test/framework.hpp>
 #include <boost/test/tree/test_unit.hpp>
 #include <boost/test/unit_test_parameters.hpp>

include/boost/test/utils/runtime/errors.hpp

@@ -37,7 +37,7 @@ namespace runtime {
 // **************             runtime::param_error             ************** //
 // ************************************************************************** //
 
-class param_error : public std::exception {
+class BOOST_SYMBOL_VISIBLE param_error : public std::exception {
 public:
     ~param_error() BOOST_NOEXCEPT_OR_NOTHROW {}
 
@@ -55,7 +55,7 @@ class param_error : public std::exception {
 
 //____________________________________________________________________________//
 
-class init_error : public param_error {
+class BOOST_SYMBOL_VISIBLE init_error : public param_error {
 protected:
     explicit    init_error( cstring param_name ) : param_error( param_name ) {}
     ~init_error() BOOST_NOEXCEPT_OR_NOTHROW {}
@@ -70,7 +70,7 @@ class input_error : public param_error {
 //____________________________________________________________________________//
 
 template<typename Derived, typename Base>
-class specific_param_error : public Base {
+class BOOST_SYMBOL_VISIBLE specific_param_error : public Base {
 protected:
     explicit    specific_param_error( cstring param_name ) : Base( param_name ) {}
     ~specific_param_error() BOOST_NOEXCEPT_OR_NOTHROW {}
@@ -155,7 +155,7 @@ SPECIFIC_EX_TYPE( missing_req_arg, input_error );
 
 #undef SPECIFIC_EX_TYPE
 
-class ambiguous_param : public specific_param_error<ambiguous_param, input_error> {
+class BOOST_SYMBOL_VISIBLE ambiguous_param : public specific_param_error<ambiguous_param, input_error> {
 public:
 #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
     explicit    ambiguous_param( std::vector<cstring>&& amb_candidates )

include/boost/test/utils/trivial_singleton.hpp

@@ -34,7 +34,7 @@ namespace unit_test {
 template<typename Derived>
 class singleton {
 public:
-    static Derived& instance() { static Derived the_inst; return the_inst; }
+    BOOST_TEST_DECL static Derived& instance();
 
     BOOST_DELETED_FUNCTION(singleton(singleton const&))
     BOOST_DELETED_FUNCTION(singleton& operator=(singleton const&))