Thread: add subscription operator if the value provide it.

[mjklaim@…]

I would like to be able to do

typedef boost::synchronized_value< boost::container::flat_map<int, int> > ValueIndex;

ValueIndex index; index[0] = 1;

and would expect that last line to be equivalent to

auto locked_index = index.synchronize(); (*locked_index)[0] = 1;

I'm not totally sure it's possible to do but it would help.