flat_map::insert(ordered_unique_range_t...) fails with move_iterators

[boost@…]

This code asserts:

flat_map<int, std::string> m1; m1.emplace(1, "one"); m1.emplace(5, "five"); m1.emplace(3, "three");

flat_map<int, std::string> m2; m2.emplace(6, "six"); m2.emplace(7, "seven"); m2.emplace(8, "eight");

m1.insert(

boost::container::ordered_unique_range_t(), std::make_move_iterator(std::begin(m2)), std::make_move_iterator(std::end(m2)));

assert(m1[6] == "six"); <- fails, m1[6] is empty

insert() accesses the iterator multiple times, trying to determine if it can insert a range of values in a burst.

[Ion Gaztañaga]

Thanks for the report. I've reproduced it and found that due to the internal representation of flat_map using a custom pair, a conversion was triggered when dereferencing the iterator when inserting. Fixed in:

[develop 5013f3f] Fixes #9931 ("flat_map::insert(ordered_unique_range_t...) fails with move_iterators")

[anonymous]

It doesn't seem to be fixed in boost 1.57.0, the example code still asserts for me.

[Ion Gaztañaga]

Let me know if:

​https://github.com/boostorg/container/commit/f47bf08ccc9b64da1e6afa6da8ab4e2147ecede8

solves the issue. Thanks.

[viboes]

What about closing this or moving it to support?

[Ion Gaztañaga]

Closing as fixed as there is no error report since the last fix.