c++ - 调用类的函数，但作为参数传递

Question

我是 C++ 编程的新手(但更习惯 IDL 和 Python)。我实际上是在尝试将我已经用 IDL 编写的代码重写到 C++ 中，以提高其效率。在我的项目中，我希望从另一个类调用一个类中的函数。下面，我复制了我认为是理解问题所需的代码的重要部分。但是，我对其进行了简化以提高其清晰度。

用g++编译时，出现如下错误:

MALA.cpp: In member function ‘void MALA::update_position_MH(Model_def*, Data*, Config*, int)’:
MALA.cpp:277:52: error: no matching function for call to ‘Model_def::call_model(Data&)’
propos_model=(*model_class).call_model(*data_struc); // PROBLEM HERE! TO DEBUG!
                                                ^
In file included from MALA.h:13:0, 
                 from MALA.cpp:29:
 model_def.h:34:12: note: candidate: Eigen::VectorXd Model_def::call_model(Data*)
      VectorXd call_model(Data *data_struc); // call a model using its name
        ^
 model_def.h:34:12: note:   no known conversion for argument 1 from ‘Data’ to ‘Data*’

我不明白的是，如果我注释该行(请参阅给定代码的末尾)，代码编译时不会出错:

 propos_model=(*model_class).call_model(*data_struc); // PROBLEM HERE!

但是，为什么我也没有收到该行的错误:

vars_new=new_prop_values((*model_class).vars, m); // This works fine

将结构“Data”作为函数 call_model 的参数传递时我做错了什么？

这是简化的代码，散布在不同的文件中:

这是 model_def.h(简化版)

#include <Eigen/Dense>
#include <string>
#include "config.h"
#include "data.h"

class Model_def{
       string model_name;
       bool relax[];
       int plength[];
       VectorXd cons;
       long Ncons, Nvars, Nparams;
       string vars_names[];
       string cons_names[];
       string params_names[];
    public:
       Model_def(string m_name, bool rlx[], int plgth, VectorXd params_in, string params_in_names); // The constructor
       Eigen::VectorXd params;
       Eigen::VectorXd vars;
       Eigen::VectorXd call_model(Data *data_struc);
};

这是 model_def.cpp(简化版)

#include <Eigen/Dense>
#include <iostream>
#include <iomanip>
#include "model_def.h"

Eigen::VectorXd Model_def::call_model(Data *data_struc){

    bool passed=0;

    if(model_name == "Model_MS_Global"){
       passed=1;
       return Model_MS_Global(params, plength, (*data_struc).x); // This function is in a dedicated cpp file (not shown here)
     }

// Other things happening...
}

这是data.h

#include <Eigen/Dense>
#include <string>
struct Data{
    Eigen::VectorXd x;
    Eigen::VectorXd y;
    long Nx; // Ny is not checked but should be as long as x
    string xlabel[];
    string ylabel[];
};

这是 MALA.h(简体)

#include <Eigen/Dense>
#include <string>
#include "model_def.h"

class MALA{
    private:
        int seed; // to generate random numbers
        double epsilon1;
        Eigen::MatrixXd epsilon2;
        double A1;
        double delta;
        double delta_x;
    public:
        void update_position_MH(Model_def *model_class, Data *data_struc, Config *cfg_class, int m);
 };

这是 MALA.cpp(简化版)

void MALA::update_position_MH(Model_def *model_class, Data *data_struc, Config *cfg_class, int m){

    VectorXd vars_new;
    double* u=uniform_01(1, &seed ); // Generate uniform random number between 0 and 1
    VectorXd propos_model;

    if((*cfg_class).proposal_type == "Random"){
        vars_new=new_prop_values((*model_class).vars, m); // This works fine
    }

    propos_model=(*model_class).call_model(*data_struc); // PROBLEM HERE!

 }

Answer 1

data_struc是一个指针，call_model要的是指针，直接传就可以了。将 * 放在前面“取消引用”它并使其不再是指针。

 propos_model=(*model_class).call_model(data_struc);

或者，更好一点

 propos_model = model_class->call_model(data_struc);