c++ - 如何在 C++ 中为元编程模板编写最后的递归

Question

我写了下面的元编程模板:

template <unsigned int N, unsigned int P>
struct cutom_imagined
{ 
    static unsigned int function(unsigned int r)
    {
        return (P + N + r) * cutom_imagined<N - 1>::function(r);
    }
};

P其实就像一个常数。我应该如何为上面的例子编写最后的递归？我想它看起来应该类似于这个:

template <>
struct cutom_imagined<0, /* What should be here? */ >
{ 
    static unsigned int function(unsigned int) { return 1; }
};

但是不知道怎么写...

Answer 1

使 P 成为模板和特化的一部分。首先，递归调用是:

return (P + N + r) * cutom_imagined<N - 1, P>::function(r);

其次，特化现在是部分的:

template <unsigned int P>
struct cutom_imagined<0, P>
{
    static unsigned int function(unsigned int) { return 1; }
};