VC++2015での実行結果

auto a = malloc( 10 );
auto b = malloc( 10 );
wchar_t tmp[ 100 ];
::swprintf_s( tmp, 100, L"a = %x, b = %x \n", a, b );
::OutputDebugString( tmp );

----------------------------------------

a = 10a4f0, b = 10a508

残念でしたね