CODEWITHSUNDEEP
c++functiondefault-arguments
user12450543
user12450543

Reputation:

compiler determine argument is given or omitted

How to determine / check whether a function argument is given or omitted in compile time?

bool a_function(char* b, size_t len=0) {

      // no run time check such as if (len ......
      // just compile time check

      // ...
}

How to realize it?

Upvotes: 3

Views: 92

Answers (1)

songyuanyao
songyuanyao

Reputation: 172894

No, there's no way to know (even at run-time) the argument was specified or not for parameter with default argument in the function.

You can apply overloading, e.g.

bool a_function(char* b, size_t len) {

    // len is specified
    // do something...
}
bool a_function(char* b) {

    // len is not specified
    // do something else...
    // or call a_function with len=0 (the default value) if satisfying the requirement
}

Upvotes: 6

Related Questions