There are overloading versions of bsoncxx::builder::core::append that accepts native int32_t and int64_t.
But, calling it with a native uint is an error ("call to member function 'append' is ambiguous").

Example:
auto document = bsoncxx::builder::basic::document{};
document.append(kvp("foo", 42)); // ok
document.append(kvp("foo", 42u)); // error

Although we could use BSON value classes instead of native types, it needs more code if the type of value is a template argument.

template <class T>
void f(T value) {
document.append(kvp("foo", value));
}
f(42u); // error

Are there workarounds?
If not, should we edit the C++ driver and add these overloading functions?