When compiling with clang and libc++ on Linux, the build stops with an error because of an ambiguous call to the member function append() of the bsoncxx::builder::core class:

mongo-cxx-driver-r3.0.1/src/bsoncxx/builder/stream/value_context.hpp:70:16: error: call to member function 'append' is ambiguous
        _core->append(std::forward<T>(t));

The line that causes the call is in the src/mongocxx/collection.cpp file at line 210:

        filter_builder << "$maxTimeMS" << options.max_time()->count();
                                                             ^

The type of options.max_time() is std::chrono::milliseconds, and according to cppreference's std::chrono::duration entry, std::chrono::milliseconds is a helper type for a std::chrono::duration with an instantiation of duration</*signed integer type of at least 45 bits*/, std::milli>. This means that options.max_time()->count should return a signed integer type of at least 45 bits.

From looking at the source code of the C++ standard library implementations, the chrono header in libc++ has std::chrono::milliseconds defined as:

typedef duration<long long, milli> milliseconds;

whereas stdlibc++ has a chrono header that has it defined as

typedef duration<int64_t, milli> milliseconds;

Both of the implementations are compliant with the C++ standard. When building against stdlibc++, the parameter value returned by the count() function should match with the candidate function void append(std::int64_t value). However, in this case where the code is being built with libc++, it seems as though the long long underlying representation and value returned by count() causes it not to match with any of the candidate functions for bsoncxx::builder::core::append().

I was able to apply a static cast of int64_t to the result of the function call, and this allowed that code to compile.

filter_builder << "$maxTimeMS" << static_cast<int64_t>(options.max_time()->count());

Here are the files and lines with relevant usages of the count() function:

/tmp/source_install/mongo-cxx-driver-r3.0.1/src/mongocxx/collection.cpp:210
/tmp/source_install/mongo-cxx-driver-r3.0.1/src/mongocxx/collection.cpp:291
/tmp/source_install/mongo-cxx-driver-r3.0.1/src/mongocxx/collection.cpp:583
/tmp/source_install/mongo-cxx-driver-r3.0.1/src/mongocxx/collection.cpp:736

    filter_builder << "$maxTimeMS" << options.max_time()->count();


/tmp/source_install/mongo-cxx-driver-r3.0.1/src/mongocxx/options/modify_collection.cpp:38

    << "expireAfterSeconds" << seconds.count() << finalize);

Applying the same static cast for an int64_t allows the build to complete without any errors.