The following code:

/// \brief Test.
class Test
{
public:
    typedef std::function<void (int)> FuncTypeA;
    typedef std::function<void ()> FuncTypeB;

    /// \brief Constructor.
    ///
    /// \param a The FuncTypeA to process.
    /// \param b The FuncTypeB to process.
    Test(FuncTypeA a, FuncTypeB b = [] {})
    {}
};

causes:

warning : argument 'b' of command @param is not found in the argument list of neo::Test::Test(FuncTypeA a)