[virtuald]

Two ways of doing it. One is totally inline as you're doing it (which isn't really the C++ way of doing it).

#include <wpilib.h>

class LimitSwitch
{
public:

    LimitSwitch(UINT32 port) :
        di(port)
    {}
    
    bool getState()
    {
        return di.Get() != 0;
    }

private:
    DigitalInput di;
};

Or split into cpp/h files. Here's LimitSwitch.h:

#ifndef __LIMITSWITCH_H
#define __LIMITSWITCH_H

class LimitSwitch
{
public:

    LimitSwitch(UINT32 port); 
    
    bool getState();

private:
    DigitalInput di;
};
#endif

And LimitSwitch.cpp:

#include <wpilib.h>
#include "LimitSwitch.h"

LimitSwitch::LimitSwitch(UINT32 port) :
    di(port)
{}

bool LimitSwitch::getState()
{
    return di.Get() != 0;
}