foo.cpp:19:32: error: ISO C++ forbids declaration of 'gswap' with no type [-fpermissive]
 inline gswap ( int &x , int &y ) { int temp = x ; x = y ; y = temp ; }
                                ^
foo.cpp: In function 'int gswap(int&, int&)':
foo.cpp:19:70: warning: no return statement in function returning non-void [-Wreturn-type]
 inline gswap ( int &x , int &y ) { int temp = x ; x = y ; y = temp ; }
                                                                      ^