44 lines
970 B
C++
44 lines
970 B
C++
//
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// Created by light on 19-12-28.
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//
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#include <iostream>
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using namespace std;
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// 使用template实现IF条件判断
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template <bool cond, typename Then, typename Else> struct IF;
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template <typename Then, typename Else> struct IF<true, Then, Else> {
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typedef Then result;
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};
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template <typename Then, typename Else> struct IF<false, Then, Else> {
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typedef Else result;
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};
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// 判断奇数与偶数
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template <int N> struct isEven {
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static const auto RES = IF<N & 1 == 0, true_type, false_type>::result::value;
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};
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template <int nums1, int nums2> struct Add_ {
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static const int value = nums1 + nums2;
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};
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template <int nums1, int nums2> struct Sub_ {
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static const int value = nums1 - nums2;
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};
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// 加减
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template <bool cond, int nums1, int nums2> struct addSub {
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static const auto RES =
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IF<cond, Add_<nums1, nums2>, Sub_<nums1, nums2>>::result::value;
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};
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int main() {
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cout << isEven<10>::RES << endl;
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cout << addSub<true, 10, 2>::RES << endl;
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}
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