6月25日代码

 1 template<typename T>
 2 void swap(T &a,T &b)
 3 {
 4     T temp=a;
 5     a=b;
 6     b=temp;
 7 }
 8 int add(double a,double b)
 9 {
10     return a+b;
11 }
12 int main()
13 {
14     int ia=3;
15     double db=5.0;
16     char s1[]="good",s2[]="better";
17     int x=add(ia,db);
18     /*swap(ia,db);
19     swap(s1,s2);*/
20 }
21 //-------------------
22 template<typename T>
23 T max(T a,T b)
24 {
25     return a<b?b:a;
26 }
27 //const T&a与T const&a等价
28 //----------------------------------------
29 #include<iostream>
30 template<typename T>
31 T const& max(T const& a,T const& b)
32 {
33     return a<b?b:a;
34 }
35 int main()
36 {
37     int ia=3;
38     double db=5.0;
39     std::cout<<max<double>(ia,db)<<"\n";
40     std::cout<<max(static_cast<double>(ia),db)<<"\n";
41 }
42 //--------------------------------------------
43 #include<iostream>
44 template<typename T>
45 void swap(T &a,T&b)
46 {
47     T temp=a;
48     a=b;
49     b=temp;
50 }
51 int main()
52 {
53     int ia=3;
54     const int cb=5;
55     swap(ia,7);
56     swap<int>(ia,7);
57     swap(cb,7);
58     swap<const int>(ia,7);
59 }
60 //----------------
61 const char*const& max(const char*const&a,const char* const&b)
62 {
63     return std::strcmp(a,b)<0?b:a;
64 }
65 //------------------
66 void f(int *ix,int *iy,double *dx,double *dy)
67 {
68     int *ip=max(ix,iy);
69     double *dp=max(dx,dy);
70 }
71 //-----------------------------------
72 #include<iostream>
73 template<typename T>
74 T const& max(T const&a,T const&b)
75 {
76     return a<b?b:a;
77 }
78 template<typename T>
79 T*const& max(T*const&a,T*const&b)
80 {
81     return *a<*b?b:a;
82 }
83 const char*const&max(const char* const&a,const char*const&b)
84 {
85     return std::strcmp(a,b)<0?b:a;
86 }
87 int main()
88 {
89     int ia=3,ib=7;
90     char*s1="hello";
91     char*s2="hell";
92     std::cout<<*max(&ia,&ib)<<"\n";
93     std::cout<<max(s1,s2)<<"\n";
94     std::cout<<max(ia,ib)<<"\n";
95 }

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