mat33 MatA, MatB, MatC;

MatA = MatB * MatC;

C:...SFunction.cpp:21: error: C2666: 'arma::Mat<eT>::operator =' : 3 overloads have similar conversions
    with
    [
        eT=double
    ]
    c:...includearmadilloarmadillo_bits/Mat_bones.hpp(724): could be 'const arma::Mat<eT> &arma::Mat<eT>::fixed<fixed_n_rows,fixed_n_cols>::operator =(const arma::Mat<eT>::fixed<fixed_n_rows,fixed_n_cols> &)'
    with
    [
        eT=double,
        fixed_n_rows=3,
        fixed_n_cols=3
    ]
    c:...includearmadilloarmadillo_bits/Mat_bones.hpp(82): or       'const arma::Mat<eT> &arma::Mat<eT>::operator =(const arma::Mat<eT> &)'
    with
    [
        eT=double
    ]
    c:...includearmadilloarmadillo_bits/Mat_meat.hpp(4652): or       'const arma::Mat<eT> &arma::Mat<eT>::operator =<arma::mat33,arma::mat33,arma::glue_times>(const arma::Glue<T1,T2,glue_type> &)'
    with
    [
        eT=double,
        T1=arma::mat33,
        T2=arma::mat33,
        glue_type=arma::glue_times
    ]
    while trying to match the argument list '(arma::mat33, const arma::Glue<T1,T2,glue_type>)'
    with
    [
        T1=arma::mat33,
        T2=arma::mat33,
        glue_type=arma::glue_times
    ]

mat33 MatA, MatB, MatC;

MatA = mat33(MatB * MatC);