Compile error on Green Hills: container_detail::flat_tree has no member "insert"

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The following lines cause issue on GHS C++14 compiler (lines 1218 and 1225):

https://github.com/boostorg/container/blob/83bb62fed3aca489e447e394f3b23c272712ecb7/include/boost/container/detail/flat_tree.hpp#L1215-L1227

Specifically, yields the following errors:

\boost_1_66_0\boost/container/detail/flat_tree.hpp", line 1131: error #135:
          class template "boost::container::container_detail::flat_tree<Value,
          KeyOfValue, Compare, AllocatorOrContainer>" has no member "insert"
        this->insert( boost::make_move_iterator(source.begin())
              ^

\boost_1_66_0\boost/container/detail/flat_tree.hpp", line 1138: error #135:
          class template "boost::container::container_detail::flat_tree<Value,
          KeyOfValue, Compare, AllocatorOrContainer>" has no member "insert"
        this->insert( boost::make_move_iterator(source.begin())
              ^

I'm not 100% sure on the solution, but think it might be replacing this->insert with this->insert_unique/insert_equal?

Thank you!

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I've submitted a PR (#101) with my proposed fix (namely, replacing the two calls to insert() with insert_unique() and insert_equal(), respectively). It passes all boost::container unit tests, but wanted to verify that this was the actual intent of these functions, and would like to know if this is a valid solution (or if another approach should be considered instead).

Thank you!