c ++ set<>类对象.使用自己的比较器给出错误:C2804:二进制“运算符<"参数太多 [英] c++ set<> of class objects. Using own comparer giving error: C2804: binary 'operator <' has too many parameters

问题描述

我编写了如下的c ++代码:

I wrote a c++ code as follows:

#include<iostream>
#include<string>
#include<set>
using namespace std;

class data{
    int i;
    float f;
    char c;
public:
    data();
    data(int i,float f,char c);
};

data::data(int i,float f,char c){
    this->i=i;
    this->f=f;
    this->c=c;
};

class LessComparer{
    bool operator<( const data& a1, const data& a2 ) const{
        return( a1.i < a2.i ||
            (!(a1.i > a2.i) && (a1.f < a2.f)) ||
            (!(a1.i > a2.i) && !(a1.f > a2.f) && (a1.c < a2.c)));
    }
};

int main(){
    set<data,LessComparer> s;
    set<data,LessComparer>::iterator it;
    s.insert(data(1,1.3,'a'));
    s.insert(data(2,2.3,'b'));
    s.insert(data(3,3.3,'c'));
    if((it=s.find(data(1,1.3,'a'))!=s.end())
        cout<<(*it).i;
    cin.get();
    return 0;
}

编译时，第一个错误为:

On compilation it is giving first error as:

error: C2804: binary 'operator <' has too many parameters

LessComparer类中的许多其他错误.

and so many other error in class LessComparer.

我是这种超载的新手.请帮助我更正代码.

I'm new to such overloading. Please help me in correcting the code.

谢谢.

推荐答案

LessComparer需要实现operator()而不是operator<

LessComparer needs to implement operator() not operator<

bool operator()( const data& a1, const data& a2 ) const

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