On Tue, Mar 15, 2016 at 8:58 PM, Phil Bouchard <philippeb8@gmail.com> wrote:
Yes you're right. I need to make my references const.
[snip]
Thanks for the clarifications.
No problem. Remember the goal isn't to provide convoluted interfaces that are strange to people who are used to a simpler convention established in the C++ standard library (or Boost, or any other library that supports C++ allocator concepts). The Allocator class template in the example you have is a valid C++ stateful allocator. Observe how it is used with existing C++ standard library facilities that are allocator aware: int c1 = 0, c2 = 0; vector<char, Allocator<char> > v(Allocator<char>(c1, c2)); list<int, Allocator<int> > l(Allocator<int>(c1, c2)); function<void(int)> f(allocator_arg, Allocator<void>(c1, c2), [](int){ }); auto p = allocate_shared<double>(Allocator<double>(c1, c2), 1.5); With your root_ptr, the interface for creation should be equally simple. No temporaries required. No extremely long type definitions required. And certainly no expressions that look like: new (temporary) Type(temporary, ...) (i.e. an expression that looks like 'temporary' is both the subject of the placement-new and an argument to the constructor of Type). Glen