template <class T> class circuit{
private:
vector<T> components;
string type;
public:
complex<double> getImpedance();
};
complex<double> circuit<circuitComponent>::getImpedance() {
// function to calculate impedance in trivial case of components all in series/parallel
}
complex<double> circuit<circuit>::getImpedance() {}
我正在尝试编写一个能够计算电阻器，电容器和电感器的任意电路（复数）阻抗的程序。
对于所有组件彼此串联/并联的电路，这是微不足道的。但是，这通常不正确。对于具有串联和并联组件混合的更复杂电路，我希望能够将电路描述为电路集合（即子电路/嵌套电路）。
所以，我正在尝试为可以包含组件向量的电路编写一个类，或一个电路向量。我试图编写一个模板类来执行此操作，但是当我尝试为电路电路（我计划递归执行）的情况定义getImpedance（）函数时，我得到一个错误，因为编译器没有t知道给子电路的类型（即在电路中，内部电路没有已知的类型）。
所以，我的问题是，有没有办法递归提供模板参数？
非常感谢任何帮助。
威尔
编辑：到目前为止，我的完整代码是
#include<iostream>
#include<string>
#include<stdlib.h>
#include<cmath>
#include<vector>
#include <type_traits>
#include<complex>
using namespace std;
// Declare pi as const.
const double pi(3.1415927);
// A class for general circuit components.
class circuitComponent {
protected:
// The component type, its impedance, and the frequency of the AC current passing through it.
string componentType;
complex<double> impedance;
double frequency;
public:
circuitComponent(string compName, complex<double> imp, double freq) : componentType(compName), impedance(imp), frequency(freq) {}
virtual ~circuitComponent() {};
virtual void setImpedance(const complex<double>&) = 0;
// Functions to return the impedance and the frequency.
virtual complex<double> getImpedance() = 0;
virtual double getFrequency() = 0;
};
// A class for resistors, derived from circuitComponent.
class resistor : public circuitComponent{
protected:
double resistance;
public:
resistor() : circuitComponent("resistor",complex<double>(0,0), 0), resistance(0) {}
resistor(double res, double freq) : circuitComponent("resistor", complex<double>(res, 0), freq), resistance(res) {}
~resistor() {}
// A function to set the impedance of the component. Also alters the resistance accordingly.
void setImpedance(const complex<double>& imp){
// Deals with case of non-pure-real impedance assignment.
if (imp.imag() != 0){
cerr << "Cannot assign impedance with non-zero imaginary component to a resistor." << endl;
}
else {
resistance = imp.real(); impedance = resistance;
}
}
// Functions to return the impedace and the frequency of the resistance.
complex<double> getImpedance() { return impedance; }
double getFrequency() { return frequency; }
};
// A class for capacitors.
class capacitor : public circuitComponent{
private:
double capacitance;
public:
capacitor() : circuitComponent("capacitor", complex<double>(0, 0), 0), capacitance(0) {}
capacitor(double cap, double freq) : circuitComponent("capacitor", complex<double>(0, -1 / (2.0*pi*frequency*cap)), freq), capacitance(cap) {}
~capacitor() {}
void setImpedance(const complex<double>& imp){
if (imp.real() != 0){
cerr << "Cannot assgn impedance with non-zero real component to a capacitor." << endl;
}
else{
impedance = imp; capacitance = imp.imag(); // THIS IS INCORRECT
}
}
complex<double> getImpedance() { return impedance; }
double getFrequency() { return frequency; }
};
// A class for inductors.
class inductor : public circuitComponent{
private:
double inductance;
public:
inductor() : circuitComponent("inductor", complex<double>(0, 0), 0), inductance(0) {}
inductor(double ind, double freq) : circuitComponent("inductor", complex<double>(0,2*pi*frequency*ind), freq), inductance(ind) {}
~inductor() {}
void setImpedance(const complex<double>& imp){
if (imp.real() != 0){
cerr << "Cannot assign impedance with non-zero real component to an inductor." << endl;
}
else{
impedance = imp; inductance = imp.imag(); // THIS IS INCORRECT
}
}
complex<double> getImpedance() { return impedance; }
double getFrequency() { return frequency; }
};
template <class T> class circuit{
private:
vector<T> components;
string type;
public:
complex<double> getImpedance();
};
// For the case where the circuit (or sub-circuit) has no subcircuits, and hence is a collection of components that are ALL in parallel/series with one another.
complex<double> circuit<circuitComponent>::getImpedance() {
complex<double> impedance(0);
vector<circuitComponent>::iterator componentIter;
if (type == "s"){
for (componentIter = components.begin(); componentIter != components.end(); ++componentIter){
impedance += componentIter->getImpedance();
}
}
else if (type == "p") {
complex<double> reciprocolImpedance(0);
for (componentIter = components.begin(); componentIter != components.end(); ++componentIter){
// complex<double>(1,0) is just the number 1 expressed as a complex number.
reciprocolImpedance += (complex<double>(1,0)/componentIter->getImpedance());
}
impedance = (complex<double>(1, 0)) / reciprocolImpedance;
}
return impedance;
}
// THIS is the problem line.
complex<double> circuit<circuit>::getImpedance() {}
int main(){
string exitStr;
cin >> exitStr;
return 0;
}
答案 0 :(得分：0)
你应该记住circuit是一个模板类;所以你不能写一些东西
complex<double> circuit<circuit>::getImpedance() {}
beacuse（1）之前缺少template <>，（2）内部circuit缺少模板参数。
编写getImpedance的方法是编写通用版本，例如
template <typename T>
std::complex<double> circuit<T>::getImpedance()
{ return components.size() ? components[0].getImpedance() : 1.0; }
和circuitComponent的专用版本，例如
template <>
std::complex<double> circuit<circuitComponent>::getImpedance()
{ return components.size() ? components[0].val : 0.0; }
完整的工作示例
#include <string>
#include <vector>
#include <complex>
#include <iostream>
struct circuitComponent
{ std::complex<double> val; };
template <typename T>
class circuit
{
private:
std::vector<T> components;
std::string type;
public:
std::complex<double> getImpedance();
};
template <>
std::complex<double> circuit<circuitComponent>::getImpedance()
{ return components.size() ? components[0].val : 0.0; }
template <typename T>
std::complex<double> circuit<T>::getImpedance()
{ return components.size() ? components[0].getImpedance() : 1.0; }
int main ()
{
circuit<circuitComponent> c0;
std::cout << c0.getImpedance() << std::endl;
circuit<circuit<circuitComponent>> c1;
std::cout << c1.getImpedance() << std::endl;
}