acker.cpp

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C++ 代码 · 共 63 行

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*                            Open Watcom Project
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// developed by:
//      Erwin Unruh     [e-mail]
//      Tom Pennello    [e-mail]
//
template <int i, int j, int k>
    struct Acker_is {
    };

template <int m, int n>
    struct Acker {
        enum {
            val = m == 0 ? n+1
                         : n == 0 ? Acker<m?m-1:0,m?1:0>::val
                                  : Acker<m?m-1:0,m?Acker<n?m:0,n?n-1:0>::val : 0>::val
        };
        Acker_is< m, n, (int) val > x;
        void f() {
            int y = x;
        }
    };

struct Acker<0,0> {
    enum {
        val = 1
    };
};

void foo() {
    Acker<3,3> x;
};