pub unsafe extern "C" fn graphene_matrix_multiply(
a: *const graphene_matrix_t,
b: *const graphene_matrix_t,
res: *mut graphene_matrix_t,
)
pub unsafe extern "C" fn graphene_matrix_multiply(
a: *const graphene_matrix_t,
b: *const graphene_matrix_t,
res: *mut graphene_matrix_t,
)