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昨天我問了一個問題，當然得到了一些很好的答案。 現在我在我的項目結束，我再次卡住，無法找出答案。 我將把我的代碼中最相關的部分放在這裏，希望能夠從你們所有人那裏獲得一些見解。 要求是：我不能更改我的main.cpp中的代碼，並且我的頭文件應該儘可能簡單。爲什麼我使用operator *失敗？
有了這樣離開這裏的方法是代碼：這是我的Matrix.h文件
#ifndef MATRIX_H
#define MATRIX_H
#include <vector>
#include <iostream>
#include <math.h>
#include <complex>
using namespace std;
namespace theMatrix {
template <typename T, size_t ROWS, size_t COLS>
class Matrix {
friend class Matrix;
public:
Matrix(const T & init = T()) : elts(ROWS, vector<T>(COLS, init)) {
};
const vector<T> & operator[](int ROWS) const {
return elts[ROWS];
};
vector<T> & operator[](int ROWS) {
return elts[ROWS];
};
//matrixMult
template<size_t INNER>
Matrix & matrixMult(const Matrix<T, ROWS, INNER> & mat1, const Matrix<T, INNER, COLS> & mat2) {
for (int i = 0; i < ROWS; i++) {
for (int j = 0; j < COLS; j++) {
//elts[i][j] = 0;
for (int k = 0; k < INNER; k++) {
this->elts[i][j] += mat1.elts[i][k] * mat2.elts[k][j];
}
}
}
return *this;
};
//print function
void print(ostream & out) const {
for (int i = 0; i < ROWS; i++) {
for (int j = 0; j < COLS; j++) {
out << elts[i][j];
}
out << "\n";
}
};
private:
vector< vector<T> > elts;
};
//Operator<<
template <typename T, size_t ROWS, size_t COLS>
ostream & operator<<(ostream & out, const Matrix<T, ROWS, COLS> & elts) {
elts.print(out);
return out;
};
//Operator*
template <typename T, size_t ROWS, size_t COLS>
Matrix<T, ROWS, COLS> operator*(const Matrix<T, ROWS, COLS> & lhs, const Matrix<T, ROWS, COLS> & rhs) {
Matrix<T, ROWS, COLS> returnVal;
return returnVal.matrixMult(lhs, rhs);
};
//operator matrixMult
template <typename T, size_t ROWS, size_t INNER, size_t COLS>
inline void matrixMult(const Matrix<T, ROWS, INNER> & mat1, const Matrix<T, INNER, COLS> & mat2, Matrix<T, ROWS, COLS> & mat3) {
mat3 = matrixMult(mat1, mat2);
};
這是我的main.cpp：
#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib> // for rand()
#include "Matrix.h"
using namespace std;
using namespace theMatrix;
template <typename T, size_t ROWS, size_t COLS>
void randomize(Matrix<T, ROWS, COLS> & mat)
// Put random values in a Matrix.
// Note: It must be possible to assign T an int value.
{
for (size_t i = 0; i < ROWS; i++)
for (size_t j = 0; j < COLS; j++)
mat[i][j] = (rand() % 21) - 10; // Random number in range -10,...,+10
}
struct Complex
{
Complex(double re = 0.0, double im = 0.0) : real(re), imag(im) { }
Complex & operator+=(const Complex & rhs)
{
real += rhs.real;
imag += rhs.imag;
return *this;
}
Complex & operator-=(const Complex & rhs)
{
real -= rhs.real;
imag -= rhs.imag;
return *this;
}
Complex & operator*=(const Complex & rhs)
{
real = real * rhs.real - imag * rhs.imag;
imag = real * rhs.imag + imag * rhs.real;
return *this;
}
double real;
double imag;
};
Complex operator+(const Complex & lhs, const Complex & rhs)
{
return Complex(lhs.real + rhs.real, lhs.imag + rhs.imag);
}
Complex operator-(const Complex & lhs, const Complex & rhs)
{
return Complex(lhs.real - rhs.real, lhs.imag - rhs.imag);
}
Complex operator*(const Complex & lhs, const Complex & rhs)
{
return Complex(lhs.real * rhs.real - lhs.imag * rhs.imag, lhs.real * rhs.imag + lhs.imag * rhs.real);
}
ostream & operator<<(ostream & out, const Complex & c)
{
out << "(" << c.real << " + " << c.imag << "i)";
return out;
}
int main()
{
// Matrix multiplication tests:
Matrix<int, 2, 3> m4;
randomize(m4);
Matrix<int, 3, 5> m5;
randomize(m5);
Matrix<int, 2, 5> m6;
Matrix<int, 2, 5> m7;
matrixMult(m4, m5, m7);
out << "m6 == m4 * m5: " << (m6 == m4 * m5) << endl; // here is the first error
// Matrices of Complex:
Matrix<Complex, 2, 8> m11;
randomize(m11);
Complex c(1, -3);
Matrix<Complex, 8, 3> m12;
randomize(m12);
out << "m11 * m12: " << endl << m11 * m12 << endl; // Here is the second error
out.close();
}
我有隻有兩個錯誤，這些錯誤與我一直試圖解決好幾個小時的複雜運算符*聲明相沖突，我無法弄清楚。 下面是錯誤的：
Error 1 error C2678: binary '*' : no operator found which takes a left-hand operand of type 'nkumath::Matrix<T,ROWS,COLS>' (or there is no acceptable conversion)
Error 2 error C2678: binary '*' : no operator found which takes a left-hand operand of type 'nkumath::Matrix<T,ROWS,COLS>' (or there is no acceptable conversion)
再次感謝大家對這種幫助。
編輯：這是解決方案！我投了票。謝謝！！！
//Operator*
template <typename T, size_t ROWS, size_t INNER, size_t COLS>
Matrix<T, ROWS, COLS> operator*(const Matrix<T, ROWS, INNER> & lhs, const Matrix<T, INNER, COLS> & rhs) {
Matrix<T, ROWS, COLS> returnVal;
return returnVal.matrixMult(lhs, rhs);
};
您錯過了兩個矩陣相乘的重載運算符。我沒有看到它張貼在這裏。它正在尋找模板，行，列。對於重載的*運算符函數，您只需具有Complex，Complex。 – 2011-04-06 18:56:14
作業？聞起來像...... – 2011-04-06 18:57:35
@ 0A0D：有一個重載（'operator *（const Matrix＆lhs，const Matrix ＆rhs）'），它只是無效在這種情況下。 –
2011-04-06 19:05:41