Ensuring that Exceptions are always caught

Question

Exceptions in C++ don't need to be caught (no compile time errors) by the calling function. So it's up to developer's judgment whether to catch them using try/catch (unlike in Java).

Is there a way one can ensure that the exceptions thrown are always caught using try/catch by the calling function?

Answer 1

No.

See A Pragmatic Look at Exception Specifications for reasons why not.

The only way you can "help" this is to document the exceptions your function can throw, say as a comment in the header file declaring it. This is not enforced by the compiler or anything. Use code reviews for that purpose.

Answer 2

You shouldn't be using an exception here. This obviously isn't an exceptional case if you need to be expecting it everywhere you use this function!

A better solution would be to get the function to return an instance of something like this. In debug builds (assuming developers exercise code paths they've just written), they'll get an assert if they forget to check whether the operation succeded or not.

class SearchResult {   private:     ResultType result_;     bool succeeded_;     bool succeessChecked_;    public:     SearchResult(Result& result, bool succeeded)       : result_(result)       , succeeded_(succeeded)       , successChecked_(false)     {     }      ~SearchResult()     {       ASSERT(successChecked_);     }      ResultType& Result() { return result_; }     bool Succeeded() { successChecked_ = true; return succeeded_; } }