C++ 重载的部分模板专门化<&书信电报；操作人员

我很难专门化一个重载的函数，我可能是错的，但我会毫不犹豫地说函数模板不能部分专门化

即使可以，他们也更喜欢直接重载

另见（Herb Sutter）

---

查看它

#include <iostream>
#include <string>

template<typename DocIdType,typename DocType>
struct Document {};

template<typename DocIdType>
std::ostream & operator << (std::ostream & os, const Document<DocIdType,std::string> & doc) {
   return os << "for string";
}

template<typename DocIdType,typename DocType>
std::ostream & operator << (std::ostream & os, const Document<DocIdType,DocType> & doc) {
   return os << "for generic";
}

using namespace std;

int main(int argc, char *argv[])
{
    std::cout << Document<struct anything, std::string>() << "\n";
    std::cout << Document<struct anything, struct anything_else>() << "\n";
}

---

我可能错了，但我会毫不犹豫地说函数模板不能部分专用化

即使可以，他们也更喜欢直接重载

另见（Herb Sutter）

---

查看它

#include <iostream>
#include <string>

template<typename DocIdType,typename DocType>
struct Document {};

template<typename DocIdType>
std::ostream & operator << (std::ostream & os, const Document<DocIdType,std::string> & doc) {
   return os << "for string";
}

template<typename DocIdType,typename DocType>
std::ostream & operator << (std::ostream & os, const Document<DocIdType,DocType> & doc) {
   return os << "for generic";
}

using namespace std;

int main(int argc, char *argv[])
{
    std::cout << Document<struct anything, std::string>() << "\n";
    std::cout << Document<struct anything, struct anything_else>() << "\n";
}

#include <iostream>
#include <string>

template<typename DocIdType,typename DocType>
struct Document {};

template<typename DocIdType>
std::ostream & operator << (std::ostream & os, const Document<DocIdType,std::string> & doc) {
   return os << "for string";
}

template<typename DocIdType,typename DocType>
std::ostream & operator << (std::ostream & os, const Document<DocIdType,DocType> & doc) {
   return os << "for generic";
}

using namespace std;

int main(int argc, char *argv[])
{
    std::cout << Document<struct anything, std::string>() << "\n";
    std::cout << Document<struct anything, struct anything_else>() << "\n";
}

for string
for generic