このCOMPAREマクロを機能させるのに問題があります。修正する方法について何かアイデアはありますか?
少し人工的なサンプルです。できるだけ小さくしたかったのです。
#include <iostream>
#include <string.h>
enum rqtypes {Unknown, Monitor, Query, Snapshot };
class base {
public:
base() : type(Unknown) {}
rqtypes type;
};
class CBMonitorDeviceRequest : public base
{
public:
CBMonitorDeviceRequest() : dn(0) {}
char* dn;
};
//I want the equivalent of:
// case MonitorDeviceRequestID:
// CBMonitorDeviceRequest* pthis = static_cast<CBMonitorDeviceRequest*>(thisrq);
// if(pthis && strcmp(pthis->dn1, "1234") == 0)
// return 0;
// else
// return -1;
// break;
int main(int argc, char* argv[])
{
CBMonitorDeviceRequest* ptr = new CBMonitorDeviceRequest;
ptr->type = Monitor;
ptr->dn = new char(strlen("1234") + 1);
strcpy(ptr->dn, "1234");
#define COMPARE(id, thismsg) case id##ID: { \
CB##id * pthis = static_cast<CB##id *>(thismsg); \
if(pthis && strcmp(pthis->dn, "1234") == 0) \
std::cout << "found"; \
else \
std::cout << "not found"; \
break; } \
switch(ptr->type){
COMPARE(Monitor, ptr);
}
#undef COMPARE
return 0;
}
私は例えば:
(46) : error C2065: 'MonitorID' : undeclared identifier
(46) : error C2051: case expression not constant
(46) : error C2065: 'CBMonitor' : undeclared identifier
(46) : error C2065: 'pthis' : undeclared identifier
(46) : error C2061: syntax error : identifier 'CBMonitor'
(46) : error C2065: 'pthis' : undeclared identifier
(46) : error C2065: 'pthis' : undeclared identifier
(46) : error C2227: left of '->dn' must point to class/struct/union/generic type
gcc -EI getの使用:#30 "macro_fun2.cpp" int main(int argc、char * argv []){CBMonitorDeviceRequest * ptr = new CBMonitorDeviceRequest; ptr->type=モニター; ptr-> dn = new char(strlen( "1234")+ 1); strcpy(ptr-> dn、 "1234"); #45 "macro_fun2.cpp" switch(ptr-> type){case MonitorID:{CBMonitor * pthis = static_cast(ptr); if(pthis && strcmp(pthis-> dn、 "1234")== 0)モニター=クエリ; elseMonitor=スナップショット; 壊す; }; }
0を返します。}
*** By the way I changed code to to avoid the massive printing of iostream by preprocessor - otherwise -E printing would have been huge.
#define COMPARE(id, thismsg) case id##ID: { \
CB##id * pthis = static_cast<CB##id *>(thismsg); \
if(pthis && strcmp(pthis->dn, "1234") == 0) \
id = Query; \
else \
id = Snapshot; \
break; } \