Duplicate Symbol Error involving a struct

[jmadsen]

My code is a little too long to put here.

Somewhere in the implementation file of my base class I am causing the duplicate symbol error below:

ld: duplicate symbol _pressureTable in /var/folders/8t/hqtf6z356sdfn9hcrzhf75s00000gn/T//ccwhIMIX.o and /var/folders/8t/hqtf6z356sdfn9hcrzhf75s00000gn/T//ccFpslXQ.o for architecture x86_64

Here is the pressureTable struct:

struct tableData
{
double sat_value;
double v_f;
double v_g;
double u_f;
double u_g;
double u_fg;
double h_f;
double h_g;
double h_fg;
double s_f;
double s_g;
double s_fg;
} pressureTable, temperatureTable;

Examples of what I am doing with the struct:

tableData ThermodynamicPowerCycle::UseSaturatedWaterPressureTable(float pressure)
{
while(true) {
int number = pressureMap.count(pressure);
if(number == 1) {
pressureTable = pressureMap.find(pressure)->second;
return pressureTable;
} else {
AppendSaturatedWaterPressureTable(pressure);
}
}

}

void ThermodynamicPowerCycle::AppendSaturatedWaterPressureTable(float pressure)
{
std::cout << "Would you like to manually specifically enter values (1) or enter two sets for interpolation (2)?" << std::endl;
short choice;
do {
std::cin >> choice;
}while(choice < 1 || choice > 2);
for(int i=0; i<choice; i++) {
std::cout << "For Pressure: " << pressure << ":" << std::endl;
std::cout << "Input the saturation temperature in Celsius" << std::endl;
std::cin >> pressureTable.sat_value;
std::cout << "Input specific volume for fluid phase and vapor phase in m3/kg. e.g. 0.01 5" << std::endl;
std::cin >> pressureTable.v_f >> pressureTable.v_g;
std::cout << "Input internal energy for fluid phase and vapor phase in kJ/kg" << std::endl;
std::cin >> pressureTable.u_f >> pressureTable.u_g;
std::cout << "Input enthalpy for fluid phase and vapor phase in kJ/kg" << std::endl;
std::cin >> pressureTable.h_f >> pressureTable.h_g;
std::cout << "Input entropy for fluid phase and vapor phase in kJ/kg*K" << std::endl;
std::cin >> pressureTable.s_f >> pressureTable.s_g;

pressureTable.u_fg = pressureTable.u_g - pressureTable.u_f;
pressureTable.h_fg = pressureTable.h_g - pressureTable.h_f;
pressureTable.s_fg = pressureTable.s_g - pressureTable.s_f;

pressureMap[pressure] = pressureTable;
}

if(choice == 2) {
Interpolate(pressure, pressureMap);
}
isSWPTappended = true;
}



As you may see, I am constantly redefining the struct and associating it with a map defined as:


std::map<float,tableData> pressureMap, temperatureMap;



I'm not seeing any thing risky here but maybe I'm not aware of it. This is my first time using a technique like this. I can post more code if it would help, however most of it is along these lines. Any help would be greatly appreciated. Thanks.

[LB]

Did you define pressureTable twice or more by mistake?

Also, wrap your code inside [code]code tags[/code] to make it easier to read (syntax highlighting)

[jmadsen]

To my knowedge, pressure table is only defined once in header file as:

struct tableData
{
double sat_value;
double v_f;
double v_g;
double u_f;
double u_g;
double u_fg;
double h_f;
double h_g;
double h_fg;
double s_f;
double s_g;
double s_fg;
} pressureTable, temperatureTable;

[jmadsen]

So I got this problem fixed. Apparently the error is in the last line. The struct should be modified to be:

struct tableData
{
    double sat_value;
    double v_f;
    double v_g;
    double u_f;
    double u_g;
    double u_fg;
    double h_f;
    double h_g;
    double h_fg;
    double s_f;
    double s_g;
    double s_fg;
};

e.g. not defining "pressureTable" and "temperatureTable" in the last line of the struct definition. I defined the

tableData pressureTable;

locally in each function, not trying a singular definition in the header file; although I expect that will work.