c++ - boost::make_shared causes access violation -

i have visual studio 2008 c++ application armv4i windows mobile 6 i'm using boost::shared_ptr<> manage large object (4kb). unfortunately, boost::make_shared<> causes access violation exception.

my code:

struct foo {     char a[ 4 * 1024 - 1 ]; };  int _tmain( int argc, _tchar* argv[] ) {     boost::shared_ptr< foo > f = boost::make_shared< foo >(); // access violation     return 0; } 

the exception callstack:

test.exe!boost::detail::sp_ms_deleter<o>::sp_ms_deleter<o>(void) line: 60, byte offsets: 0x18   c++ test.exe!boost::make_shared<o>(void) line: 106, byte offsets: 0x5c  c++ test.exe!wmain(int argc = 1, wchar_t** argv = 0x01b40060) line: 81, byte offsets: 0x18  c++ test.exe!mainwcrtstartup(hinstance__* hinstance = 0x00000003, hinstance__* hinstanceprev = 0x00000000, unsigned short* lpszcmdline = 0x00000003, int ncmdshow = 0) line: 188, byte offsets: 0x94    c++ 

the location of exception (boost\smart_ptr\make_shared.hpp):

template< class t > class sp_ms_deleter {     /* snip! */         public:     sp_ms_deleter(): initialized_( false )     {    // line: 60  = null     }      /* snip! */ 

this issue not occur when compiling x86 windows. issue not occur when using shared_ptr this:

boost::shared_ptr< foo > f1 = boost::shared_ptr< foo >( new foo ); 

can explain what's going on , why breaking on armv4i windows mobile 6?

thanks, paulh

probably it's alignment issue. don't know details of implementation, make_shared<>() tries allocate shared_ptr<> object , pointed-to object in 1 single allocation. causes 1 of 2 objects end @ address isn't aligned should be.

this explain why crashes on arm: architecture has stricter alignment requirements normal pc hardware. if int or pointer ends on "strange" address, program crash on arm while pc happily access data.