C++ 奇怪的错误， "no conversion from ' int' 到 'int (__cdecl *)(float,float)' "

Question

首先，这是我关于 stackoverflow 的第一个问题。我正在努力完成家庭作业，但我不知道自己做错了什么。

当我第二次尝试运行一个函数时，出现错误“没有从‘int’到‘int (__cdecl *)(float,float)’的转换”。该函数应该返回 0、-1 或 +1，并在 if/else 语句中使用。

这是我指的代码块...

    #include <iostream>
using namespace std;


////this function returns a -1 if the left pan has a weight more than the right, a 0 if the weights of the two pans are equal, and a +1 if the right pan has a greater weight than the left
int weigh(float leftpan, float rightpan)
{
 //compare the pan weights, return value
}


float findOddRock(float r1, float r2, float r3, float r4, float r5, float r6, float r7)
{
    //first weigh
    float first_leftpan = r1 + r2;
    float first_rightpan = r3 + r4;

    weigh(first_leftpan, first_rightpan);
    if(weigh == 0){
        cout << "this program is working so far";
        float second_leftpan = r5; //this brings up an error for some reason
        float second_rightpan = r6;
        weigh(second_leftpan, second_rightpan);


//here's where I get the error, no conversion from 'int' to 'int (__cdecl *)(float,float)'
        if(weigh == 0){   //be careful here, changed from second_weigh to weigh
            float third_leftpan = r5; 
            float third_rightpan = r7;
            weigh(third_leftpan, third_rightpan);
 }

//
int main()
{
 //find the light rock
 findOddRock(2.0, 2.0, 2.0, 2.0, 2.0, 2.0, 1.0);
 }

Answer 1

看起来您想将函数的返回值与 0 进行比较:

 weigh(first_leftpan, first_rightpan);
    if(weigh == 0){

尝试做:

if(weigh(first_leftpan, first_rightpan) == 0){

weight 函数也没有返回任何东西..解决这个问题。

如果您尝试使用 == 比较两个 float ，请注意 float 不准确。