File content as of revision 0:bf289fbff1dd:

#include "mbed.h"

BusOut mbedleds(LED1,LED2,LED3,LED4);
//BusOut/In is faster than multiple DigitalOut/Ins

class Nav_Switch
{
public:
    Nav_Switch(PinName up,PinName down,PinName left,PinName right,PinName fire);
    int read();
//boolean functions to test each switch
    bool up();
    bool down();
    bool left();
    bool right();
    bool fire();
//automatic read on RHS
    operator int ();
//index to any switch array style
    bool operator[](int index) {
        return _pins[index];
    };
private:
    BusIn _pins;

};
Nav_Switch::Nav_Switch (PinName up,PinName down,PinName left,PinName right,PinName fire):
    _pins(up, down, left, right, fire)
{
    _pins.mode(PullUp); //needed if pullups not on board or a bare nav switch is used - delete otherwise
    wait(0.001); //delays just a bit for pullups to pull inputs high
}
inline bool Nav_Switch::up()
{
    return !(_pins[0]);
}
inline bool Nav_Switch::down()
{
    return !(_pins[1]);
}
inline bool Nav_Switch::left()
{
    return !(_pins[2]);
}
inline bool Nav_Switch::right()
{
    return !(_pins[3]);
}
inline bool Nav_Switch::fire()
{
    return !(_pins[4]);
}
inline int Nav_Switch::read()
{
    return _pins.read();
}
inline Nav_Switch::operator int ()
{
    return _pins.read();
}

Nav_Switch myNav( p9, p6, p7, p5, p8); //pin order on Sparkfun breakout

int main()
{
    while(1) {
        //with pullups a button hit is a "0" - "~" inverts data to leds
        mbedleds = ~(myNav & 0x0F); //update leds with nav switch direction inputs
        if(myNav.fire()) mbedleds = 0x0F; //special all leds on case for fire (center button)
        //or use - if(myNav[4]==0) mbedleds = 0x0F; //can index a switch bit like this
        wait(0.02);
    }
}