问题
I'm writing some stuff using the tr1 namespace in VS2008. What will happen when C++xx becomes ratified? Has this happened before with other C++ revisions? Will the tr1 stuff still work or will I have to change all of my include? I realize that I'm making the very large assumption that this ratification will someday occur. I know that most likely none of you work for MS or contribute to GCC, but if you have experience with these kinds of changes, I would appreciate the advice.
回答1:
std::tr1 will become part of std in C++1x (std::tr1::shared_ptr becomes std::shared_ptr, etc). std::tr1 will continue to exist as long as that compiler claims to implement TR1. At some point your compiler may drop that claim, and drop std::tr1 as a result. This probably will never happen.
std::tr1 has already been "copied" into namespace std in Visual Studio 2010 Beta (via a using directive)
回答2:
The Wikipedia entry for C++0x says "A large part of the new libraries are defined in the document C++ Standards Committee's Library Technical Report (called TR1), which was published in 2005. Various full and partial implementations of TR1 are currently available using the namespace std::tr1. For C++0x they will be moved to namespace std. However, as TR1 features are brought into the C++0x standard library, they are upgraded where appropriate with C++0x language features that were not available in the initial TR1 version. Also, they may be enhanced with features that were possible under C++03, but were not part of the original TR1 specification."
回答3:
tr1 is not part of any standard (the paper it is shorthand for never was accepted) - it's just a convention that some compilers provide. They will almost certainly go on providing it long into the future.
来源：https://stackoverflow.com/questions/2002752/what-will-happen-to-namespace-tr1-when-c-xx-is-approved