fix pico build

src/CPU.h

@@ -19,7 +19,8 @@ public:
 	virtual void checkpoint(Stream &s) = 0;
 	virtual void restore(Stream &s) = 0;
 
-	inline bool halted() { return _halted; }
+	inline bool halted() const { return _halted; }
+	inline Memory::address pc() const { return PC; }
 
 	Memory &memory() const { return _mem; }
 

src/hardware.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <functional>
+
 #if defined(HARDWARE_H)
 #include HARDWARE_H
 #else

src/pia.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <functional>
+
 // Motorola 6820 / 6821 PIA
 // https://en.wikipedia.org/wiki/Peripheral_Interface_Adapter
 class PIA {

src/ps2_raw_kbd.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <functional>
+
 class matrix_keyboard {
 public:
 	virtual void up(uint8_t) = 0;

src/r65emu.h

@@ -1,6 +1,6 @@
-#ifndef __R65EMU_H__
-#define __R65EMU_H__
+#pragma once
 
+#include <functional>
 #include "memory.h"
 #include "CPU.h"
 #include "ram.h"
@@ -20,5 +20,3 @@
 #include "hw_serial_kbd.h"
 #include "serial_dsp.h"
 #include "hw_serial_dsp.h"
-
-#endif

src/serial_kbd.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <functional>
+
 class serial_kbd {
 public:
 	virtual int read() = 0;

src/via.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <functional>
+
 class VIA {
 public:
 	VIA(): _timer1(false), _timer2(false), _t1(0), _t2(0), _t1_latch(0),