Method insert

external/parallel_hashmap/phmap.h:1302–1304

              typename std::enable_if<IsDecomposable<T>::value, int>::type = 0,
              T* = nullptr>
    std::pair<iterator, bool> insert(T&& value) {
        return emplace(std::forward<T>(value));
    }

    // This overload kicks in when the argument is a bitfield or an lvalue of
    // insertable and decomposable type.