on Sun Apr 22 2012, Eric Niebler <eric-AT-boostpro.com> wrote:
On 4/22/2012 6:21 AM, Beman Dawes wrote:
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3350.html claims:
"Boost's range library focuses on defining a set of Range concepts that allow Containers to be Ranges. Because Containers are heavy-weight, this forces Boost to use references for all of their uses of Ranges, including Ranges that are captured by Range Adapters. This worked fine in C++98, where users couldn't name the types of the Range Adapters in order to declare local variables, but with C++11's auto keyword, users can now save adapted ranges. Since Boost's adapted ranges capture references to their arguments, which can be temporaries, this is no longer a safe design."
Is this claim correct?
I imagine so. Expression template libraries (including std::valarray!) have the same problem.
Another way of saying it is, "no more correct than the same complaint about any other type that captures a reference to its ctor argument (e.g. std::ref)." -- Dave Abrahams BoostPro Computing http://www.boostpro.com