class - Qt 4 C++ Getting an error when using 3 classes that use each other, error: field `m_Employer' has incomplete type -

-

i'm in desperate need of , direction. been trying compile, battling due fact there 3 classes , not hundreds on how includes/forward declarations should work here.

the error marked in person.h.

in addition error, there warning i've marked in main.cpp.

this console app.

thank in advance.

person.h

#ifndef person_h #define person_h #include <qstring>  class employer;  class person {     public:         person(qstring name);         qstring tostring() const;         void setposition(employer newe, position newp);         position getposition() const;     private:         qstring m_name;         bool m_employed;         position m_position;         employer m_employer; //--> error: field `m_employer' has incomplete type. };  #endif // person_h

person.cpp

#include "employer.h" #include "position.h" #include "person.h"   person::person(qstring name) : m_name(name), m_employed(false), m_position(""), m_employer("") { }    void person::setposition(employer newe, position newp) {     m_position = newp;     m_employed = true;     m_employer = newe; }  position person::getposition()const {     return (m_employed ? m_position : position("professional nose-picker")); }  qstring person::tostring()const {     return m_name + ", employed: " + (m_employed ? "yes" : "no") + ", position: " + getposition().tostring(); }

employer.h

#ifndef employer_h #define employer_h #include <qstring>  //class position; //class person;  class employer {     public:         employer(qstring name, qstring market = "");         void hire(person &newhire, position pos);         qstring tostring() const;     private:         qstring m_name;         qstring m_market; };  #endif // employer_h

employer.cpp

#include "employer.h" #include "person.h" #include "position.h"   employer::employer(qstring name, qstring market) : m_name(name), m_market(market) { }  qstring employer::tostring()const {     return m_name + (m_market != "" ? ", market: " + m_market : ""); }  void employer::hire(person &newhire, position pos) {     newhire.setposition(*this, pos); }

position.h

#ifndef position_h #define position_h #include <qstring>  class position {     public:         position(qstring name, qstring desc = "");         qstring tostring() const;     private:         qstring m_name;         qstring m_desc; };  #endif // position_h

position.cpp

#include "position.h"  position::position(qstring name, qstring desc)         :m_name(name), m_desc(desc) {}  qstring position::tostring()const {     return m_name + (m_desc != "" ? ", description: " + m_desc : ""); }

main.cpp

#include <qtcore/qcoreapplication> #include <qtextstream> #include "position.h" #include "person.h" //--warning -> in file included main.cpp:4: #include "employer.h"    int main(int argc, char *argv[]) {     qcoreapplication a(argc, argv);     qtextstream cout(stdout);      person bob("bob");     employer devco("dev co");      cout << bob.tostring() << endl;     bob.setposition(is, position("developer", "software eng"));     cout << bob.tostring() << endl;     cout << devco.tostring() << endl;      return a.exec(); }

the person class needs know employer , needs employer.h included in rather class forward declaration.

in case person needs know size of employee class have employee stored inside class.

if wanted decouple classes , use forward declaration person have contain pointer (raw or smart) employer.


Comments

Post a Comment

Popular posts from this blog

python - Scipy curvefit RuntimeError:Optimal parameters not found: Number of calls to function has reached maxfev = 1000 -

-
Image
i want make logharitmic fit. keep getting runtime error: optimal parameters not found: number of calls function has reached maxfev = 1000 i use following script. can tell me go wrong? use spyder still beginner. import math import matplotlib mpl scipy.optimize import curve_fit import numpy np #data f1=[735.0,696.0,690.0,683.0,680.0,678.0,679.0,675.0,671.0,669.0,668.0,664.0,664.0] t1=[1,90000.0,178200.0,421200.0,505800.0,592200.0,768600.0,1036800.0,1371600.0,1630800.0,1715400.0,2345400.0,2409012.0] f1n=np.array(f1) t1n=np.array(t1) plt.plot(t1,f1,'ro',label="original data") # curvefit def func(t,a,b): return a+b*np.log(t) t=np.linspace(0,3600*24*28,13) popt, pcov = curve_fit(func, t, f1n, maxfev=1000) plt.plot(t, func(t, *popt), label="fitted curve") plt.legend(loc='upper left') plt.show() your original data t1 , f1 . therefore curve_fit should given t1 second argument, not t . popt, pcov = curve_fit(func,...
Read more

binding - How can you make the color of elements of a WPF DrawingImage dynamic? -

-
we have need make vector graphic images change color of elements within graphic @ runtime. seem setting colors based on either static or dynamic resource values wouldn't work. want have multiple versions of same graphic, each abilty set graphic elements (path, line, etc) different colors don't think dynamic resource approach work. leaves data binding seems right approach. update graphic use data binding expr instead of hard-coded brush color so: <drawingimage x:key="graphic1"> <drawingimage.drawing> <drawinggroup> <drawinggroup.children> <geometrydrawing geometry="f1 m 8.4073,23.9233l"> <geometrydrawing.pen> <pen linejoin="round" brush="{binding line1brush, mode=oneway}"/> </geometrydrawing.pen> </geometrydrawing> <geometrydrawing geometry="f1 m 3.6875,2.56251l"> <geometrydrawing....
Read more

c# - How to add a new treeview at the selected node? -

-
i have treeview 4 levels; parent, child, grandchild, great-grandchild. selectednode @ grandchild level. what i'm trying create new "treeview" @ grandchild - no, dont wnat create new node "selectednode" (grandchild). should somelike this: parent child grandchild (new treeview) parent grandchild great-grandchild child great-grandchild child grandchild grandchild it similar parent table mother , father went off , had new childern different spouse other spouse of there existing children. private sub populaterootlevel() ' query find first round of parent populatenodes(dt, jcatreeview.nodes) end sub private sub populatenodes(byval dt datatable, byval nodes treenodecollection) each dr datarow in dt.rows dim tn new treenode() tn.text = dr("title").tostring()...
Read more