Odd 2-way system

BareBonesUno.ino

template< uint8_t PinValue >
class Input
{
public:
	static constexpr uint8_t Pin = PinValue;

private:
	uint8_t previousState;
	uint8_t currentState;

public:

	void setup(void)
	{
		pinMode(Pin, INPUT);
		currentState = digitalRead(Pin);
		previousState = currentState;
	}

	uint8_t getCurrentState(void) const
	{
		return this->currentState;
	}

	uint8_t getPreviousState(void) const
	{
		return this->previousState;
	}

	bool hasChanged(void) const
	{
		return this->previousState != this->currentState;
	}

	bool isActive(void) const
	{
		return this->currentState != 0;
	}

	void update(void)
	{
		this->previousState = this->currentState;
		this->currentState = digitalRead(Pin);
	}
};

template< uint8_t PinValue >
class Output
{
public:
	static constexpr uint8_t Pin = PinValue;

public:

	void setup(void)
	{
		pinMode(Pin, OUTPUT);
	}

	void write(uint8_t value)
	{
		digitalWrite(Pin, value);
	}
};

Output<4> output;
Input<8> input;
Input<12> button;

void setup()
{
	Serial.begin(9600);
	while(!Serial);

	output.setup();
	input.setup();
	button.setup();
}

void loop()
{
	input.update();
	button.update();
	
	if(input.hasChanged())
	{	
		Serial.println(F("Change"));
		Serial.print(F("Previous: "));
		Serial.print(input.getPreviousState());
		Serial.print(F(", Current: "));
		Serial.println(input.getCurrentState());
	}
	
	if(button.hasChanged())
		Serial.println(F("Change Button"));

	if(button.isActive())
	{
		output.write(1);
	}
	else
	{
		output.write(0);
	}

	delay(100);
}

BSD3ClauseLicence.txt

Copyright 2018 Pharap

Redistribution and use in source and binary forms, with or 
without modification, are permitted provided that the following 
conditions are met:

    1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above 
copyright notice, this list of conditions and the following disclaimer 
in the documentation and/or other materials provided with the 
distribution.

    3. Neither the name of the copyright holder nor the names of its 
contributors may be used to endorse or promote products derived from 
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, 
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 
USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

main.cpp

#include "Pokitto.h"

DigitalOut output = DigitalOut(EXT0);
DigitalIn input = DigitalIn(EXT4);

int main (void)
{
	using Pokitto::Core;
	using Pokitto::Buttons;
	using Pokitto::Display;

    Core::begin();
    while (Core::isRunning())
        if (Core::update())
		{
        	if(Buttons::aBtn())
			{
				output.write(1);
			}
			else
			{
				output.write(0);
			}

			if(input.read() != 0)
			{
				Display::println("Input: 1");
			}
			else
			{
				Display::println("Input: 0");
			}
		}
}