Hi, I'm a happy user of boost::extension library. Thanks Jeremy Pack et al. for this great work, and hope it'll be accepted by Boost soon. My extension library is dowloaded from http://boost-extension.blogspot.com/ (August 14, 2008 Link), which works great for me when compiled with "-O0" optimization flag in g++ (my version: i686-apple-darwin9-g++-4.0.1). But, when I compile with -O2 and access type_map object through member template function, g++ seems to optimize away the initialization logic for 'type_map', and I'd get signal assertion of EXC_BAD_ACCESS. Here's my test program: 65 struct MyDict { 66 boost::extensions::type_map mTypeDict; 67 template< typename T > 68 T & refInstance() { mTypeDict.get<T>(); } 69 }; 70 71 typedef std::set<int> IntSetType; 72 73 void test_MyDict_1_mem_data_access() { 74 MyDict testObj; 75 std::cout << "------ 1 " << std:: endl; 76 IntSetType &rIntSet = testObj.mTypeDict.get<IntSetType>(); 77 std::cout << "------ 2 " << std:: endl; 78 std::cout << "rIntSet.size() is " << rIntSet.size() << std::endl; 79 std::cout << "------ 3 " << std:: endl; 80 rIntSet.insert (123); 81 std::cout << "------ 4 " << std:: endl; 82 std::cout << "rIntSet.size() is now " << rIntSet.size() << std::endl ; 83 std::cout << "------ 5 " << std:: endl; 84 } 85 86 void test_MyDict_2_mem_func_access() { 87 MyDict testObj; 88 std::cout << "====== 1 " << std:: endl; 89 IntSetType &rIntSet = testObj.refInstance<IntSetType>(); 90 std::cout << "====== 2 " << std:: endl; 91 std::cout << "rIntSet.size() is " << rIntSet.size() << std::endl; 92 std::cout << "====== 3 " << std:: endl; 93 rIntSet.insert (123); 94 std::cout << "====== 4 " << std:: endl; 95 std::cout << "rIntSet.size() is now " << rIntSet.size() << std::endl ; 96 std::cout << "====== 5 " << std:: endl; 97 } This test program runs without any problem when compiled with "-O0"; but with "-O2" compiler flag, "test_MyDIct_1_mem_data_access()" is still run ok as expect, but "test_MyDict_2_mem_func_access()" halts at line 93. Here's the output when run under gdb: ------ 1 ------ 2 rIntSet.size() is 0 ------ 3 ------ 4 rIntSet.size() is now 1 ------ 5 ====== 1 ====== 2 rIntSet.size() is 86 ====== 3 Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_PROTECTION_FAILURE at address: 0x0000005e std::_Rb_tree::insert_unique (this=0x56, __v=@0xbffff24c) at testHpcDictByType.c:871 871 _Link_type __x = _M_begin(); (gdb) So my question is, what's wrong with accessing boost::extension::type_map through "MyDict::refInstance<T>()" here? In g++ "-O2" mode, why does the direct access to "MyDict::mTypeDict" is ok, while "MyDict::refInstance<T>()" is not ? I'm not sure if this is a generic g++ optimization problem, or specific to boost::extension library. But, for me, it seems to happen only for type_map data structure, but not others. Thanks for shedding any light on this. --- Jeffrey