Implementing the Shunting Yard Algorithm

What I already have correctly done :
Code:
```class token
{
public:
token(const token& _t){num = _t.num;opcode = _t.opcode;};
token(std::string _in); //For parts of the input string
token(double n){opcode='n';num=n;};//
token(void){opcode=0;num=0;};

char opcode;  // 'n' for operands and the first character in operators
double num; //value for operands and no of operands for operators
int oppr;  //for precedence

token operator+(token t){num+=t.num;return *this;};
token operator-(token t){num-=t.num;return *this;};
token operator*(token t){num*=t.num;return *this;};
token operator/(token t){num/=t.num;return *this;};

};```
Everything works correctly in this.

Say I want a function
Code:
`std::deque<token> infix_to_rpn(std::deque<token>)`
I wrote the following ...but it doesn't work and I am not able to follow what is inside the containers ...when debugging.
Code:
```deque<token> infix_to_rpn(deque<token> infix)
{
deque<token> rpn,op_s;//op_s for operator stack
token *t,*s_t;//s_t for stack temp
while(!infix.empty())
{
t = new token(infix.front());
if(t->opcode=='n')rpn.push_back(*t);
else if(t->opcode!='('&&t->opcode!=')'&&t->opcode!=','&&t->num==1)
{
op_s.push_back(*t);
}
else if(t->opcode == ',')
{
bool flag(1);
while(flag)
{
s_t = new token(op_s.back());
if(s_t->opcode=='('){flag=0;break;}
op_s.pop_back();
rpn.push_back(*s_t);

}
}
else if(t->opcode!='('&&t->opcode!=')'&&t->opcode!=','&&t->num==2)
{
bool flag(1);
while(flag)
{
s_t = new token(op_s.back());
if(t->oppr>=s_t->oppr)
{
op_s.pop_back();
rpn.push_back(*s_t);
}
else{flag=0;rpn.push_back(*t);break;}
}
}
else if(t->opcode == '(')
{
rpn.push_back(*t);
}
else if(t->opcode == ')')
{
bool flag(1);
while(flag)
{
s_t = new token(op_s.back());
if(s_t->opcode!='(')
{
op_s.pop_back();
rpn.push_back(*s_t);
}
else if (s_t->opcode == '(')
{
op_s.pop_back();
flag = 0;
break;
}
}
}
else if(!op_s.empty())
{
while(!op_s.empty())
{
s_t = new token(op_s.back());
op_s.pop_back();
rpn.push_back(*s_t);
}
}
}
return rpn;
}```
I am 'almost' sure that I followed the steps of the algorithm correctly ! ...though it is clear that I didn't..