id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
11970	Use perfect forwarding for object_pool	djpeaco@…	Chris Newbold	"boost::object_pool::construct uses a code generation system to create versions of that method that take up to some arbitrary number of input parameters. With C++11/14 it is possible to do the same using perfect forwarding, which would allow any number of input parameters using a single template method, and without bloating the hpp.

I think this would also solve a related problem I am having. The object that I am trying to construct using the object_pool takes a unique_ptr as an input parameter to it's constructor (it is taking ownership of it):
{{{
class Node {}

class Tree {
    Tree(std::unique_ptr<Node> root, int foo, int bar) : 
        m_root(std::move(root)) {}
private:
    std::unique_ptr<Node> m_root;    
}

void makeTrees()
{
    boost::object_pool<Tree> treePool;
    std::unique_ptr<Node> node (new Node());
    Tree* tree = treePool.construct (node, 1, 2);
}
}}}

In the current implementation, the compiler gives an error because object_pool::construct doesn't call std::move on root when newing the tree:
{{{
/usr/local/include/boost/pool/detail/pool_construct.ipp(258): error: function ""std::unique_ptr<_Tp, _Dp>::unique_ptr(const std::unique_ptr<_Tp, _Dp> &) [with _Tp=Node, _Dp=std::function<void (Node *)>]"" (declared at line 273 of ""/usr/include/c++/4.8.5/bits/unique_ptr.h"") cannot be referenced -- it is a deleted function
    try { new (ret) element_type(a0, a1, a2); }
}}}

I think (but am not certain) that using perfect forwarding would allow this."	Feature Requests	new	To Be Determined	pool	Boost 1.61.0	Problem		object_pool