gcc：g ++与模板模板朋友官僚主义

Question

在标题view.h中：

template<class S, template<typename> class V>
void Operate(S c, const V<S>& vx);

template<class T, template<typename> class U>
class ViewBase
{
    template<class S, template<typename> class V>
    friend void Operate(S c, const V<S>& vx);
};

template<class T>
class ViewTypeA : public ViewBase<T, ViewTypeA>
{

};

template<class T>
class ViewTypeB : public ViewBase<T, ViewTypeB>
{

};

template<class S, template<typename> class V>
void Operate(S c, const V<S>& vx)
{

}

在cpp：

#include "view.h"

int main(int argc, char **argv)
{
    Operate(5, ViewTypeA<int>());
    Operate(5, ViewTypeB<int>());
}

gcc（使用-std = gnu ++ 11编译）会出错：

Build: Debug in codeblocks (compiler: GNU GCC Compiler)
main.cpp||In function ‘int main(int, char**)’:

main.cpp|7|error: call of overloaded ‘Operate(int, ViewTypeA&)’ is ambiguous

main.cpp|7|note: candidates are:

view.h|25|note: void Operate(S, const V&) [with S = int; V = ViewTypeA]

view.h|9|note: void Operate(S, const V&) [with S = int; V = ViewTypeA; T = int; U = ViewTypeA]

---

main.cpp|8|error: call of overloaded ‘Operate(int, ViewTypeB)’ is ambiguous

main.cpp|8|note: candidates are:

view.h|25|note: void Operate(S, const V&) [with S = int; V = ViewTypeB]

view.h|9|note: void Operate(S, const V&) [with S = int; V = ViewTypeB; T = int; U = ViewTypeA]

---

Build failed: 2 error(s), 0 warning(s) (0 minute(s), 0 second(s))

的问题：

类模板参数根本不应该出现 - 我是对的吗？模糊性似乎基于类的模板参数。