C++：将模板回调方法传递给另一个方法：无法将‘<unresolved overloaded function type> 转换为指针

Question

我有一个容器，用于存储包含模板回调的结构。同时回调签名不包含模板参数。插入时，出现错误：

cannot convert ‘<unresolved overloaded function type>’ to ‘smb1_subdecoder::send_subflow_premature_end_msg_t’ {aka ‘void (smb1_subdecoder::*)(long unsigned int, unsigned char, long unsigned int, unsigned char)’}

note:   initializing argument 4 of  
‘void smb1_subdecoder::store_subflow_bunch_on_open(
    smb1_subdecoder::handle_t, uint64_t, CIFS_RESOURCE_TYPE, 
    smb1_subdecoder::send_subflow_premature_end_msg_t, 
    smb1_subdecoder::send_subflow_premature_end_msg_t)’
    send_subflow_premature_end_msg_t send_subflow_premature_end_rq_msg,
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`

插入代码（此处错误）：

store_subflow_bunch_on_open(
    handle(response_msg.file_id), response_msg.msg_id, 
    static_cast<CIFS_RESOURCE_TYPE>(parm_open2_rsp->resource_type),
    &send_subflow_premature_end_msg<ntdec_cifs_close_request>,
    &send_subflow_premature_end_msg<ntdec_cifs_close_response>);

定义：

存储方式：

void smb1_subdecoder::store_subflow_bunch_on_open(
    handle_t handle, uint64_t subflow_msg_id, CIFS_RESOURCE_TYPE resource_type,
    send_subflow_premature_end_msg_t send_subflow_premature_end_rq_msg,
    send_subflow_premature_end_msg_t send_subflow_premature_end_rsp_msg) { ... }

send_subflow_premature_end_msg_t:

typedef void (smb1_subdecoder::*send_subflow_premature_end_msg_t)
                    (uint64_t, uint8_t, uint64_t, uint8_t);

用于发送提前结束消息的模板函数（签名不依赖于上述模板参数）：

template<class NTDEC_END_OBJECT_T>
void smb1_subdecoder::send_subflow_premature_end_msg(uint64_t subflow_msg_id, uint8_t close_reason,
                                                     uint64_t header_msg_id, uint8_t side)
{
    NTDEC_END_OBJECT_T end_msg;
    _d_smb->proto_fill(end_msg, subflow_msg_id);
    end_msg.header_msg_id = header_msg_id;
    if (_d_smb->transport() == decoder_smb::TRANSPORT::NETBIOS)
    {
        const auto* netbios_msg = _d_smb->get_proto_parent<ntdec_object>();
        if (netbios_msg)
            set_parent_msg_id(end_msg, netbios_msg->msg_id);
    }
    end_msg.side = (side == -1) ? _d_smb->get_last_data_side() : side;

    _d_smb->stream().send_message(end_msg);
}

Answer 1

当 constructing a pointer to member.

时，您必须明确地使用 class 名称限定非静态成员的名称

（强调我的）

If the operand is a qualified name of a non-static member, e.g. &C::member, the result is a prvalue pointer to member function or pointer to data member of type T in class C. Note that neither &member nor C::member nor even &(C::member) may be used to initialize a pointer to member.

例如

store_subflow_bunch_on_open(
    handle(response_msg.file_id), response_msg.msg_id, 
    static_cast<CIFS_RESOURCE_TYPE>(parm_open2_rsp->resource_type),
    &smb1_subdecoder::send_subflow_premature_end_msg<ntdec_cifs_close_request>,
//   ^^^^^^^^^^^^^^^^^
    &smb1_subdecoder::send_subflow_premature_end_msg<ntdec_cifs_close_response>);
//   ^^^^^^^^^^^^^^^^^

C++：将模板回调方法传递给另一个方法：无法将‘<unresolved overloaded function type> 转换为指针

C++: passing the template callback method into the other method: cannot convert ‘<unresolved overloaded function type> to pointer

c++

templates

callback