pforth: use extern "C" for IO functions

So we can implement them in C++.

diff --git a/csrc/pf_io.h b/csrc/pf_io.h
index db8fd92..b87d739 100644 (file)
--- a/csrc/pf_io.h
+++ b/csrc/pf_io.h
@@ -24,6 +24,9 @@
 #define PF_CHAR_XON    (0x11)
 #define PF_CHAR_XOFF   (0x13)
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 int  sdTerminalOut( char c );
 int  sdTerminalEcho( char c );
 int  sdTerminalFlush( void );
@@ -31,6 +34,9 @@ int  sdTerminalIn( void );
 int  sdQueryTerminal( void );
 void sdTerminalInit( void );
 void sdTerminalTerm( void );
+#ifdef __cplusplus
+}
+#endif
 
 void ioInit( void );
 void ioTerm( void );