VC6和模板错误
我正在重载运算符＆lt;＆lt;为类实现类似接口的流：
template<typename T>
CAudit& operator << ( const T& data ) {
audittext << data;
return *this;
}
CAudit& operator << ( LPCSTR data ) {
audittext << data;
return *this;
}
class CAudit
{
public:
/* TODO_DEBUG : doesn't build!
template<typename T>
CAudit& operator << ( const T& data ) {
audittext << data;
return *this;
}*/
~CAudit() { write(); }//If anything available to audit write it here
CAudit& operator << ( LPCSTR data ) {
audittext << data;
return *this;
}
//overload the << operator to allow function ptrs on rhs, allows "audit << data << CAudit::write;"
CAudit& operator << (CAudit & (*func)(CAudit &))
{
return func(*this);
}
void write() {
}
//write() is a manipulator type func, "audit << data << CAudit::write;" will call this function
static CAudit& write(CAudit& audit) {
audit.write();
return audit;
}
private:
std::stringstream audittext;
};
CAudit audit
audit << "Billy" << write;
没有找到相关结果
已邀请:
4 个回复
钨蜡唤喉晤
#include "stdafx.h" #include <string> #include <iostream> #include <sstream> #include <windows.h> class CAudit { std::ostringstream audittext; void do_write() {} public: ~CAudit() { do_write(); } // types for manipulators struct Twrite {}; // manipulators static Twrite write; // implementations of << template<typename T> CAudit& operator << ( const T& data ) { audittext << data; return *this; } CAudit& operator << ( LPCSTR data ) { audittext << data; return *this; } CAudit& operator << ( Twrite& ) { do_write(); return *this; } }; // static member initialization CAudit::Twrite CAudit::write; int main(int argc, char* argv[]) { CAudit a; int i = 123; const char * s = "abc"; a << i << s << CAudit::write; return 0; }稳赣苍卯改
class CAudit { template<typename T> CAudit& operator<<(T const& t) { this->print(t); return *this; } private: void print(int); void print(LPCSTR); void print(CAudit & (*func)(CAudit &)); template<typename T> print(T const&); };找到单个成员模板。其他候选人不是其他课程和内置插入的成员。他们应该明白这个模板更糟糕。你里面的第二次查询只需要处理叫的成员。壬驴拿歪竞
template<typename T> CAudit& operator << (T data ) { audittext << data; return *this; }#include <iostream> using namespace std; class CAudit{ public: CAudit(){} template< typename T > CAudit &operator<<(T arg); CAudit &operator<<(char s); }; template< typename T> void oldLog(T arg){ cout << arg; } template< typename T > CAudit &CAudit::operator<<(T arg){ oldLog( arg ); return *this; } CAudit &CAudit::operator<<(char arg){ oldLog( arg ); return *this; } int main(){ CAudit e; e << "Hello"; e << 'T'; return 0; }社攻取墟槽
#include "stdafx.h" #include <string> #include <iostream> #include <sstream> #include <windows.h> class CAudit { std::ostringstream audittext; public: std::string getAuditText() const { return audittext.str(); } template<typename T> CAudit& operator << ( const T& data ) { audittext << data; return *this; } CAudit& operator << ( int data ) { audittext << data; return *this; } CAudit& operator << ( LPCSTR data ) { audittext << data; return *this; } }; int main(int argc, char* argv[]) { CAudit a; int i = 123; const char * s = "abc"; a << i; a << s; std::cout << "audittext is: '" << a.getAuditText() << "'n"; return 0; }