Modify flat associative containers to be adaptors if the allocator argument is a container. This allows using stable_vector, small_vector, static_vector as underlying containers.

test/flat_set_test.cpp

@@ -57,25 +57,6 @@ template class flat_multiset
    , allocator<test::movable_and_copyable_int>
    >;
 
-namespace container_detail {
-
-//Instantiate base class as previous instantiations don't instantiate inherited members
-template class flat_tree
-   < test::movable_and_copyable_int
-   , identity<test::movable_and_copyable_int>
-   , std::less<test::movable_and_copyable_int>
-   , test::simple_allocator<test::movable_and_copyable_int>
-   >;
-
-template class flat_tree
-   < test::movable_and_copyable_int
-   , identity<test::movable_and_copyable_int>
-   , std::less<test::movable_and_copyable_int>
-   , allocator<test::movable_and_copyable_int>
-   >;
-
-}  //container_detail {
-
 //As flat container iterators are typedefs for vector::[const_]iterator,
 //no need to explicit instantiate them