boost::bind & boost::function with partial args

问题:

I post you an example of what I want to do, that is easier to explain in this way

    void myPrinter(const char* text, int number){            
            printf("\n%s %d\n", text, number);
        }

    int main() {

        char *someText="test";        

       boost::function<void(int my_number)> functionWithSavedArgs = boost::bind(&myPrinter, someText, ?????);

       //then I have to call my function with saved args and give to it only variable "number" like:
       int myBeautifulNumber = 2012;
       functionWithSavedArgs(myBeautifulNumber);
       // echo: test 2012
     }

Any ideas?

回答1:

Just skip that argument.

   boost::function<void(int my_number)> functionWithSavedArgs
        = boost::bind(&myPrinter, someText);

This binds only the first argument.

If you wanted to bind only the second one, you would need a placeholder:

   boost::function<void(int my_number)> functionWithSavedArgs
         = boost::bind(&myPrinter, _1, someNumber);