Thread: Stroustrup Chapter 6 class Token Example Link Error

Hello everyone, I'm having a linking error with:

Code:

#include "../../../std_lib_facilities.h"

//------------------------------------------------------------------------------

class Token {
public:
    char kind;        // what kind of token
    double value;     // for numbers: a value 
    Token(char ch)    // make a Token from a char
        :kind(ch), value(0) { }    
    Token(char ch, double val)     // make a Token from a char and a double
        :kind(ch), value(val) { }
};

//------------------------------------------------------------------------------

 Token get_token();  // PROBLEM MAY BE HERE

//------------------------------------------------------------------------------

vector<Token> tok;    // we'll put the tokens here

//------------------------------------------------------------------------------

int main()
{

    while (cin) {
        Token t = get_token();
        tok.push_back(t);
    }
    // ...
    

    for (int i = 0; i<tok.size(); ++i) {
        if (tok[i].kind=='*') {    // we found a multiply!
            double d = tok[i-1].value*tok[i+1].value;
            // now what?
        }
    }
}

Getting:
1>D:\Documentos\Projectos\Programming P & P w C++\Libro\6.3 Example Tokenizing\Debug\6.3 Example Tokenizing.exe : fatal error LNK1120: 1 unresolved externals
1>
1>Build FAILED.

Pleas advise

It should have given you a list of the unresolved symbols.

And yes, you will need to implement get_token().
It isn't enough just to state that it exists.