我在编译以下代码时遇到了这个错误。
经过一些研究并阅读不同情况下的类似错误后,我想出了我需要的解决方案。
但我并没有完全理解错误的根本原因和修复方法。
template <typename T>
class TestA {
int a;
T temp;
protected:
int b;
public:
int c;
TestA(T te): a{10}, b{20}, c{30}, temp{te} {}
int geta(){ return a; }
int getb(){ return b; }
int getc(){ return c; }
};
template <typename T>
class TestB {
int atb;
T tempb;
protected:
int btb;
public:
int ctb;
TestB(T te) atb{10}, btb{20}, ctb{30}, tempb{te} {}
};
template <typename T>
class TestInh : public TestA<T>, public TestB<T> {
int aa;
T temptemp;
protected:
int bb;
int b;
public:
int cc;
TestInh(T te) : TestA<T>{te}, TestB<T>{te}, bb{10000}, b{-1000} {}
int get_total() {
// The error happens here!
return geta();
}
};
int main(int argc, char const *argv[]) {
char text = 'a';
TestInh<char> test(text);
//std::cout << test.geta() << std::endl;
std::cout << test.get_total() << std::endl;
//std::cout << test.c << std::endl;
return 0;
}
编译此代码时,我收到此错误:
testtemplate.cc: In member function ‘int TestInh<T>::get_total()’:
testtemplate.cc:54:32: error: there are no arguments to ‘geta’ that depend on a template parameter, so a declaration of ‘geta’ must be available [-fpermissive]
int get_total() {return geta();}
^
testtemplate.cc:54:32: note: (if you use ‘-fpermissive’, G++ will accept your code, but allowing the use of an undeclared name is deprecated)
通过调用即可解决this->geta()
而不仅仅是geta()
,但我不完全理解为什么编译器无法解决这个问题。
有人可以解释一下为什么吗?