将 const char* 作为模板参数传递

Why can't you pass literal strings in here? I made it work with a very slight workaround.

template<const char* ptr> struct lols {
    lols() : i(ptr) {}
    std::string i;
};
class file {
public:
    static const char arg[];
};
decltype(file::arg) file::arg = __FILE__;
// Getting the right type declaration for this was irritating, so I C++0xed it.

int main() {
    // lols<__FILE__> hi; 
    // Error: A template argument may not reference a non-external entity
    lols<file::arg> hi; // Perfectly legal
    std::cout << hi.i;
    std::cin.ignore();
    std::cin.get();
}

推荐答案

因为这不是一个有用的实用程序.由于它们不是模板参数的允许形式，因此目前不起作用.

lols<"A"> n;

// might fail because a different object address is passed as argument!
lols<"A"> n1 = n;