C++ Error upon run “Description Resource Path Location Type expected ';' at end of member declaration operand.h line 13” and "expected ')' before '&' token operand.h line 13".

operand.h***

#ifndef OPERAND_H

#define OPERAND_H

class Operand: public Expression{

public:

static Expression* parse(stringstream& in); ←---------------Line 13

};

#endif // OPERAND_H

parse.h****

using namespace std;

#ifndef PARSE_H

#define PARSE_H

string parseName(stringstream& in);

#endif // PARSE_H

parse.cpp****

#include

#include

#include

#include

#include "parse.h"

using namespace std;

string parseName(stringstream& in){

char alnum;

string name = "";

in >> ws;

while (isalnum(in.peek())){

in >> alnum;

name += alnum;

}

return name;

}

operand.cpp****

#include

#include

#include

#include

#include

using namespace std;

#include "expression.h"

#include "subexpression.h"

#include "operand.h"

#include "variable.h"

#include "literal.h"

#include "parse.h"

#include "or.h"

#include "and.h"

#include "equality.h"

#include "greaterThan.h"

#include "lessThan.h"

#include "ternary.h"

#include "negation.h"

Expression* Operand::parse(stringstream& in){

char paren;

int value;

in >> ws;

if (isdigit(in.peek())){

in >> value;

Expression* literal = new Literal(value);

return literal;

}

if (in.peek() == '('){

in >> paren;

return SubExpression::parse(in);

}

else

return new Variable(parseName(in));

return 0;

}

Project2.cpp****

#include

#include

#include

#include

#include

#include

using namespace std;

unordered_map symbolTable;

int evaluateExpression(stringstream& expression);

int evaluateSubExpression(stringstream& subExpression) {

char operation;

subExpression >> operation;

if (operation == '(') {

return evaluateExpression(subExpression);

} else {

string variable;

subExpression >> variable;

return symbolTable[variable];

}

}

int evaluateExpression(stringstream& expression) {

char operation;

expression >> operation;

int result = evaluateSubExpression(expression);

while (expression >> operation) {

if (operation == ')') {

return result;

}

int rightOperand = evaluateSubExpression(expression);

if (operation == '+') {

result += rightOperand;

} else if (operation == '-') {

result -= rightOperand;

} else if (operation == '*') {

result *= rightOperand;

} else if (operation == '/') {

result /= rightOperand;

}

}

return result;

}

void parseAssignments(stringstream& assignment) {

string variable;

char assignOp;

int value;

while (assignment >> variable >> assignOp >> value) {

symbolTable[variable] = value;

}

}

int main() {

ifstream inputFile("input.txt");

if (!inputFile) {

cerr << "Failed to open the input file." << endl;

return EXIT_FAILURE;

}

string line;

while (getline(inputFile, line)) {

stringstream expression(line);

char paren;

expression >> paren;

if (paren != '(') {

cerr << "Invalid expression: " << line << endl;

continue;

}

int result = evaluateExpression(expression);

cout << "Expression: " << line << "\nValue = " << result << endl;

}

inputFile.close();

return 0;

}