如何调用静态函数? [英] How to call a static function?

问题描述

我在我的类 Matrix 中定义了 2 个函数，如下(在 Matrix.hpp 中)

I have defined 2 functions in my class Matrix as follows (in Matrix.hpp)

static Matrix MCopy( Matrix &a );   
static Matrix MatInvert( Matrix &x )
static double MatDet( Matrix &x ); // Matdef function

在我的 Matrix.Cpp 文件中，我将这些函数定义如下:

In my Matrix.Cpp file, I defined these functions as follows:

Matrix Matrix::MatCopy( Matrix &a )
{
Matrix P( a.getRow() , a.getCol() , Empty );
int j=0;
while( j != P.getRow() ){    
    int i=0;
    while( i != P.getCol() ){    
        P(j,i)=a(j,i);
        ++i;
    }
    ++j;
}
return P;
}

Matrix Matrix::MatInvert( Matrix &x )
{
Matrix aa = Matrix::MatCopy(x); // i got error message here
int n = aa.getCol();

Matrix ab(n,1,Empty);
Matrix ac(n,n,Empty);
Matrix ad(n,1,Empty);

if(MatLu(aa,ad)==-1){
    assert( "singular Matrix" );
    exit(1);
}
int i=0;
while( i != n ){    
    ab.fill(Zero);
    ab (i,0)=1.0;
    MatRuecksub(aa, ab,ac,ad,i);
    ++i;
}
 return ac; 
}

好的，这是我的 MatDef 函数

ok this is the my MatDef function

double Matrix::MatDet( Matrix &x )
{
double result;
     double vorz[2] = {1.0, -1.0};
int n = x.getRow();
Matrix a = Matrix::MatCopy(x);
Matrix p( n, 1, Empty);

int i = MatLu(a, p);
if(i==-1){  
    result = 0.0;
}
else {  
    result = 1.0;
    int j=0;
    while(j != n){    
        result *= a( static_cast<int>(p(j,0)) ,j);
        ++j;
    }
    result *= vorz[i%2];
}
  return result;
 }

但是当我编译这个时，我得到一个错误告诉我:

but when I compile this, I get an error telling me that:

line 306:no matching function for call to ‘Matrix::Matrix[Matrix]’:
note: candidates are: Matrix::Matrix[Matrix&]
note:in static member function ‘static double Matrix ::MatDet[Matrix&]’:

我不明白问题出在哪里，因为我是 C++ 编程的新手，所以请帮助我修复这个错误.

I can not understand what the problem is since I am new to C++ programming, so please help me in fixing this error.

我用过的地方

  Matrix aa = Matrix::MatCopy(x);

它显示与第 306 行相同的错误消息，但有不同的注释，所以我认为 MatDef 不是问题.请提出您的意见以解决此问题.谢谢！

It shows same error message like line 306 but with different notes so I think MatDef is not a problem. Please give your comments to solve this. Thanks!

推荐答案

如果你有一个叫做 A 的类并且它有一个静态函数 foo 你可以这样调用它

If you have a class called A and it has a static function foo you would call it this way

A::foo();

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