<snip>
I want to wrap some existing C code with C++. The function I want to call
back is declareed like this:
struct X {
double foo(double x , void * p);
};
Idealy I would like to use lambda to remove the void* and replace it with
_1, _2 etc. But I am not sure how > that works with callbacks.
Use boost::bind or boost::lambda::bind. For example:
// An instance of x
X x;
// A binary function
boost::function fBinary;
// A unary function
boost::function fUnary;
// A nullary function
boost::function fNullary;
// Bind x.foo to binary function
fBinary = boost::bind(&X::foo, boost::ref(x), _1, _2);
// Bind x.foo to unary function "hardcoding" second parameter
fUnary = boost::bind(&X::foo, boost::ref(x), 5.25, _1);
// Bind x.foo to nullary function "hardcoding" first and second parameter
int i = 5;
fNullary = boost::bind(&X::foo, boost::ref(x), 5.25, &i);
// Execute binary function passing both arguments
fBinary(5.25, &i);
// Execute unary function passing 1 argument
fUnary(&i);
// Execute nullary function
fNullary();
Hope this helps,
-delfin
