我有一个大量使用 shared_ptr 和 STL 的 C++ 代码。一个常见的标题说

#include<boost/shared_ptr.hpp>
using boost::shared_ptr;  // for shared_ptr
using namespace std;      // for STL

我想现在切换到 c++0x 以利用语言功能，使用 gcc 4.6 和 -std=c++0x。但是现在也有 std::shared_ptr，导致未指定的 shared_ptr 出现歧义(boost::shared_ptr vs std::shared_ptr).

当切换到 std::shared_ptr 时，像这样:

#include<memory>
using namespace std;      // for STL; also imports std::shared_ptr

然后我遇到了 boost::python 的问题，它只能与 boost::shared_ptr 一起正常工作(至少没有进一步摆弄):

/usr/include/boost/python/object/make_ptr_instance.hpp:30:52: error: no matching function for call to 'get_pointer(const std::shared_ptr<Cell>&)'

因此我的问题是

• 如果有一个简单的解决方案来解决 boost::shared_ptr 和 std::shared_ptr 之间的歧义(除了现在不使用 c++0x)，还有
• 如果 boost::shared_ptr 最终只是 std::shared_ptr 的别名；那会自动解决我的问题。

谢谢!

最佳答案

您需要为共享指针类定义独立函数“get_pointer”，以便它与 Boost Python 一起使用。 (请注意，这使您能够编写自己的共享指针，并且仍然可以使用 Boost Python:这是一种有意识的设计努力，旨在防止不同的 Boost 库紧密耦合)。

您可能会使用 boost tr1 兼容性 header 获得它，但我还没有尝试过。

http://boost.cowic.de/rc/pdf/tr1.pdf

When Boost.TR1 is configured to make use of your standard library's native TR1 implementation, then it doesn't do very much: it just includes the appropriate header.

When Boost.TR1 is using the Boost implementation of a particular component, then it includes the appropriate Boost header(s) and imports the necessary declarations in namespace std::tr1 with using declarations. Note that only those declarations that are part of the standard are imported: the implementation is deliberately quite strict about not including any Boost-specific extensions in namespace std::tr1, in order to catch any portability errors in user code. If you really need to use Boost-specific extensions then you should include the Boost headers directly and use the declarations in namespace boost:: instead. Note that this style of implementation is not completely standards-conforming, in particular it is not possible to add user-defined template specializations of TR1 components into namespace std::tr1. There are also one or two Boost libraries that are not yet fully standards conforming, any such non-conformities are documented in the TR1 by subject section. Hopefully, occurrences of non-standard behavior should be extremely rare in practice however.

If you use the standard conforming header includes (in boost/tr1/tr1) then these header names can sometimes conflict with existing standard library headers (for example shared_ptr is added to the existing standard library header rather than it's own header). These headers forward on to your existing standard library header in one of two ways: for gcc it uses #include_next, and for other compilers it uses the macro BOOST_TR1_STD_HEADER(header) (defined in boost/tr1/detail/config.hpp) which evaluates to #include <../include/header>. This should work "straight out the box" for most compilers, but does mean that these headers should never be placed inside a directory called "include" that is already in your compiler's search path.

关于python - c++0x std::shared_ptr 与 boost::shared_ptr，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6568952/