boost :: make_shared和C ++ Builder VCL对象

Question

I've tried switching some C++Builder 2010 code using new to use boost::make_shared<> , as below.

Old:

boost::shared_ptr<TStringList> l(new TStringList());

New:

boost::shared_ptr<TStringList> l(boost::make_shared<TStringList>());

l->Add("foo"); //dies here

The old code works, but the new code dies when I try and use the pointer (AV, or just hangs). I've used make_shared and shared_ptr successfully before, but never with TObject descendants. Is this a known problem - perhaps something to do withe the way make_shared uses placement new() ??

Answer 1

我认为placement new的placement new确实存在问题，因为TObject对new内存分配感到满意（因为C ++ Builder的RTL在内部将C / C ++的内存例程路由到VCL项目中的Delphi RTL例程），而placement new则没有。