联盟初始化Apache模块与C++

Question

我的问题是非常相似的

Apache module command parser prototype

不过，我在apr_cmd更多初始化[]，即我有一些像

static const command_rec apr_cmds[] = 
{ 
AP_INIT_TAKE1("analytics_ip", apr_cfg_set_analytics_ip, NULL, OR_ALL, ""), 
AP_INIT_TAKE1("AuthenDenied", set_authen_denied, (void*)APR_OFFSETOF(config_rec, authen_denied), OR_AUTHCFG, ""), 
AP_INIT_FLAG("RefreshCookies", ap_set_flag_slot, (void*)APR_OFFSETOF(config_rec, refresh_cookies), OR_AUTHCFG, ""), 
{ NULL } 
}; 

对于每个初始化，我得到“无法转换为cmd_func”编译错误。

Krystof建议使用

#ifdef __cplusplus 
typedef const char *(*cmd_func) (cmd_parms *cmd, void *dummy, const char *path); 
#else 
typedef const char *(*cmd_func)(); 
#endif 

如果我这样做，第一个错误将不复存在。但是，其他错误仍然存​​在，因为我无法再次为第二个函数set_authen_denied重新定义cmd_func。

任何帮助表示赞赏。

Answer 1

删除黑客代码并使工厂功能。

namespace cmd_func_type{ 
    /** function to call for a no-args */ 
    using no_args_t = const char *(*) (cmd_parms *parms, void *mconfig); 
    /** function to call for a raw-args */ 
    using raw_args_t = const char *(*) (cmd_parms *parms, void *mconfig, const char *args); 
    /** function to call for a argv/argc */ 
    using take_argv_t = const char *(*) (cmd_parms *parms, void *mconfig, int argc, char *const argv[]); 
    /** function to call for a take1 */ 
    using take1_t = const char *(*) (cmd_parms *parms, void *mconfig, const char *w); 
    /** function to call for a take2 */ 
    using take2_t = const char *(*) (cmd_parms *parms, void *mconfig, const char *w, const char *w2); 
    /** function to call for a take3 */ 
    using take3_t = const char *(*) (cmd_parms *parms, void *mconfig, const char *w, const char *w2, const char *w3); 
    /** function to call for a flag */ 
    using flag_t = const char *(*) (cmd_parms *parms, void *mconfig, int on); 
} 
template<cmd_how args_how = NO_ARGS> 
cmd_func make_cmd_func(cmd_func_type::no_args_t f){ cmd_func re; re.no_args = f; return re; } 
template<cmd_how args_how = NO_ARGS> cmd_func make_cmd_func(cmd_func_type::raw_args_t); 
template<> 
cmd_func make_cmd_func<RAW_ARGS>(cmd_func_type::raw_args_t f){ cmd_func re; re.raw_args = f; return re; } 
template<cmd_how args_how = TAKE_ARGV> 
cmd_func make_cmd_func(cmd_func_type::take_argv_t f){ cmd_func re; re.take_argv = f; return re; } 
template<> 
cmd_func make_cmd_func<TAKE1>(cmd_func_type::take1_t f){ cmd_func re; re.take1 = f; return re; } 
template<cmd_how args_how = TAKE2> 
cmd_func make_cmd_func(cmd_func_type::take2_t f){ cmd_func re; re.take2 = f; return re; } 
template<cmd_how args_how = TAKE3> 
cmd_func make_cmd_func(cmd_func_type::take3_t f){ cmd_func re; re.take3 = f; return re; } 
template<cmd_how args_how = FLAG> 
cmd_func make_cmd_func(cmd_func_type::flag_t f){ cmd_func re; re.flag = f; return re; } 

template< 
    cmd_how args_how, typename DataPtr, typename CmdFuncType, 
    std::enable_if_t<std::is_pointer<DataPtr>::value || std::is_same<DataPtr, std::nullptr_t>::value, std::nullptr_t> = nullptr 
> 
command_rec make_command_rec(const char *name, CmdFuncType f, DataPtr cmd_data, int req_override, const char *errmsg){ 
    return {name, make_cmd_func<args_how>(f), (void*)(cmd_data), req_override, args_how, errmsg }; 
} 

例如
http://melpon.org/wandbox/permlink/6yeQNOptQHCJh5Wf