[問題] Variadic Macros + tamplate問題
開發平台(Platform): (Ex: VC++, GCC, Linux, ...)
vc 2005
問題(Question)：
定義 variadic macros 時
, 與 tamplate的 , 無法區分
#define MACRO_C(msg, ...) \
{\
ostringstream oss; \
oss << "MACRO_B: " << __VA_ARGS__ << " " << msg; \
cout << oss.str() << endl; \
}
在這行時 會把tamplate的逗號當作是上面 msg與 ...的區隔
MACRO_C("NOT " << FUN_C<int, float>(14) << " MACRO_C: " << 15 , "ERROR?");
想請教一下如何寫才能避免此情況呢
感謝
程式碼(Code)：(請善用置底文網頁, 記得排版)
#include <sstream>
#include <iostream>
using namespace std;
#define MACRO_A(x) \
{\
ostringstream oss; \
oss << x; \
cout << oss.str() << endl; \
}
#define MACRO_B(...) \
{\
ostringstream oss; \
oss << "MACRO_B: " << __VA_ARGS__; \
cout << oss.str() << endl; \
}
#define MACRO_C(msg, ...) \
{\
ostringstream oss; \
oss << "MACRO_B: " << __VA_ARGS__ << " " << msg; \
cout << oss.str() << endl; \
}
string FUN_B(int x)
{
ostringstream oss;
oss << x;
return oss.str();
}
template<class X, class Y>
string FUN_C(X x)
{
ostringstream oss;
oss << x;
return oss.str();
}
int _tmain(int argc, _TCHAR* argv[])
{
MACRO_A("MACRO_A: " << 1 << " MACRO_A: " << 2);
MACRO_A("MACRO_A: " << FUN_B(3) << " MACRO_A: " << 4);
string c = FUN_C<int, float>(5);
MACRO_A("MACRO_A: " << c << " MACRO_A: " << FUN_B(6));
// MACRO_A("MACRO_A: " << FUN_C<int, float>(7) << " MACRO_A: " << FUN_B(8));
MACRO_B(FUN_C<int, float>(9));
MACRO_B("I AM " << FUN_C<int, float>(10) << " MACRO_B: " << 11);
MACRO_C("OK?", "MACRO_C: " << 12 << " MACRO_C: " << 13);
// MACRO_C("NOT " << FUN_C<int, float>(14) << " MACRO_C: " << 15 , "ERROR?");
return 0;
}
補充說明(Supplement)：
上面黃色兩行都會compile error
第二個ERROR屬於我敘述問題的情況
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