Are there any differences between boost::shared_ptr, std::tr1::shared_ptr and the upcoming (in C++0x) std::shared_ptr?
Will porting from one to another have any overhead or are they basically the same?
According to the Boost website, the boost::shared_ptr...
...conforms to the TR1 specification, with the only exception that it resides in namespace
boostinstead ofstd::tr1.
According to the Wikipedia C++0x page
The TR1 implementation lacked certain pointer features such as aliasing and pointer arithmetic, but the C++0x version will add these.
If your code works with the TR1/Boost version, it should work with the C++0x version (but not necessarily vice versa).
来源：https://stackoverflow.com/questions/1086798/differences-between-different-flavours-of-shared-ptr