#include <ESP8266WiFi.h>

#include "PCF8574.h"

PCF8574 pcf8574(0x38);

class PinReader {
 public:
  PCF8574 *expander;
  void read();
};

void PinReader::read() {

  Serial.println("Pin state inside init: " + String(this->expander->digitalRead(P6)));
}

void setup() {
  Serial.begin(115200);
  Serial.println();

  PinReader reader = PinReader();
  pcf8574.pinMode(P6, INPUT);
  if (pcf8574.begin()) {
    Serial.println("Begin success");
  } else {
    Serial.println("Begin FAIL");
  }
  delay(100);

  reader.expander = &pcf8574;
  reader.read();
  Serial.println("Pin state outside init: " + String(pcf8574.digitalRead(P6)));
}

void loop() {

}