Template ,compile failure

[Damon lbj]

I'm learning C++,but i meet a problem .When i use date array,my program compile failure,i don't know why(other fine)... who can do me a favor?
God bless you!
compile error:
In function ‘bool operator<(date<int>, date<int>)’:
35:15: instantiated from here
17:90: error: lvalue required as left operand of assignment

  1 #include<iostream>
  2 using namespace std;
  3 #include<string>
  4 template<class T>
  5 struct date{
  6     T year;
  7     T month;
  8     T day;
  9 public:
 10     date(T y,T m,T d):year(y),month(m),day(d){}
 11     friend ostream& operator<<(ostream& o,const date& da)
 12     {
 13         return o<<da.year<<'-'<<da.month<<'-'<<da.day;
 14     }
 15     friend bool operator<(date a,date b)
 16     {
 17         return  (a.year<b.year||a.year==b.year&&(a.month<b.month||a.month=b.    month&&a.day<b.day));
 18     }
 19 };
 20 template<class Type>
 21 Type* max(Type *a,int n)
 22 {
 23     int ma=0;
 24     for(int i=1;i<n;i++)
 25         if(a[ma]<a[i])
 26             ma=i;
 27     return a+ma;
 28 }
 29 
 30 template<>
 31 date<int>* max(date<int> a[],int n)
 32 {
 33     int ma=0;
 34     for(int i=1;i<n;i++)
 35         if(a[ma]<a[i])
 36             ma=i;
 37     return a+ma;
 38 }
 39 
 40 int main()
 41 {
 42     int a[5]={13,2,22,11,18};
 43     int * p=max(a,5);
 44     cout<<"Max="<<*p<<' '<<p<<endl;
 45     char c[5]={'f','z','v','r','s'};
 46     cout<<c[1]<<' '<<&c[2]<<endl;
 47     char * q=max(c,5);
 48     cout<<"Max="<<*q<<' '<<&q<<endl;
 49     double d[5]={13.2,2.1,22.4,11.1,18.2};
 50     double * r=max(d,5);
 51     cout<<"Max="<<*r<<' '<<r<<endl;
 52     date<int> ymd[5]={date<int>(2002,5,7),date<int>(1990,6,7),                  date<int>(2013,6,8),date<int>(2008,3,1),date<int>(2001,2,3)};
 53     date<int> * y=max(ymd,5);
 54     cout<<"Max="<<*y<<' '<<y<<endl;
 55 }
 

[LB]

It looks like your line 17 got corrupted somehow, look to the mid-right half of it and it looks wrong. Specifically, you used assignment = instead of comparison ==