Noob Geezer, copied example T6603 from Github, won't compile for me?

/*
Copyright (c) 2014 Brian Manley

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "SoftwareSerial.h"
#include <T6603.h>

T6603 sensor;

void setup() {
Serial.begin(19200);
sensor.begin(10, 11);
}

void loop() {
Serial.println(sensor.get_co2());
delay(2000);
}

/*
Copyright (c) 2014 Brian Manley

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "Arduino.h"
#include <SoftwareSerial.h>

#define MAX_ATTEMPTS 10

class T6603 {

private:
static const byte FLAG = 0xFF;
static const byte BRDCST = 0xFE;
static const byte CMD_READ = 0x02;
static const byte CMD_UPDATE = 0x03;
static const byte CMD_STATUS = 0xB6;
static const byte CMD_IDLE = 0xB9;

static const byte CO2_PPM = 0x03;
static const byte SERIL = 0x01;
static const byte ELEVATION = 0x0F;

SoftwareSerial* _serial;
int _lastReading;

public:
T6603();
~T6603();
void begin(uint8_t, uint8_t);
int get_co2(void);
byte get_status(void);
void set_idle(bool);
};

Errors:

T6603Example.cpp.o: In function __static_initialization_and_destruction_0': /Users/jamespatrick/Downloads/T6603Example.ino:24: undefined reference to T6603::T6603()'
/Users/jamespatrick/Downloads/T6603Example.ino:24: undefined reference to T6603::~T6603()' T6603Example.cpp.o: In function loop':
/Users/jamespatrick/Downloads/T6603Example.ino:32: undefined reference to T6603::get_co2()' T6603Example.cpp.o: In function setup':
/Users/jamespatrick/Downloads/T6603Example.ino:28: undefined reference to `T6603::begin(unsigned char, unsigned char)'

What error messages are you getting?? Sorry!

They are listed at bottom of my post.

The code didn't download properly for me.
I have older Imac that can't be updated to OSX 10.7 as Github requires
That may be what went wrong?

So I just copied & pasted from: https://github.com/thebrianmanley/T6603/blob/master/T6603.cpp

I see no setup() ???

#include “SoftwareSerial.h”
#include “T6603.h”

T6603::T6603() {

}

T6603::~T6603() {

if ( NULL != _serial ) {
delete _serial;
_serial = NULL;
}
}

void T6603::begin(uint8_t rx, uint8_t tx) {

_serial = new SoftwareSerial(rx, tx);
_serial->begin(19200);
}

int T6603::get_co2(void) {

_serial->overflow();
_serial->write(FLAG);
_serial->write(BRDCST);
_serial->write(0x02);
_serial->write(CMD_READ);
_serial->write(CO2_PPM);
delay(50);

for ( int attempts = 0; attempts < MAX_ATTEMPTS; attempts++ ) {

byte reading[5];
int bytesRead = 0;

while ( _serial->available() && bytesRead < 6) {
reading[bytesRead] = _serial->read();
bytesRead++;
delay(10);
}

if ( reading[0] == 0xFF && reading[1] == 0xFA ) {
int i = 0;
i |= reading[3] & 0xFF;
i <<= 8;
i |= reading[4] & 0xFF;
_lastReading = i;
return (_lastReading);
}
}

return (_lastReading);
}

byte T6603::get_status(void) {

_serial->overflow();
_serial->write(FLAG);
_serial->write(BRDCST);
_serial->write(0x01);
_serial->write(CMD_STATUS);
delay(50);

for ( int attempts = 0; attempts < MAX_ATTEMPTS; attempts++ ) {

byte reading[4];
int bytesRead = 0;

while ( _serial->available() && bytesRead < 4) {
reading[bytesRead] = _serial->read();
bytesRead++;
delay(10);
}

if ( reading[0] == 0xFF && reading[1] == 0xFA ) {
return ( reading[3] );
}
}

return (NULL);
}

void T6603::set_idle(bool onOff) {

byte cmd = onOff ? 0x01 : 0x02;

_serial->overflow();
_serial->write(FLAG);
_serial->write(BRDCST);
_serial->write(0x02);
_serial->write(CMD_IDLE);
_serial->write(cmd);
delay(50);

for ( int attempts = 0; attempts < MAX_ATTEMPTS; attempts++ ) {

byte reading[3];
int bytesRead = 0;

while ( _serial->available() && bytesRead < 3) {
reading[bytesRead] = _serial->read();
bytesRead++;
delay(10);
}

if ( reading[0] == 0xFF && reading[1] == 0xFA ) {
return;
}
}

}

Errors:

core.a(main.cpp.o): In function main': /Users/jamespatrick/Downloads/Arduino.app/Contents/Resources/Java/hardware/arduino/avr/cores/arduino/main.cpp:30: undefined reference to setup’
/Users/jamespatrick/Downloads/Arduino.app/Contents/Resources/Java/hardware/arduino/avr/cores/arduino/main.cpp:33: undefined reference to `loop’