From: "James Curran" <[EMAIL PROTECTED]>Chuck Messenger wrote:
* add_options() should use references rather than pointers
"Pointer for return value" is C semantics. In C++, pointers denote optional values. Non-const references are for return values.
I disagree *strongly*. In C and C++, the address-of syntax clearly indicates that this is a value that will be changed. Your suggestion of using a non-const reference would require me to check the header file to find the signature of _every_single_F#$^%ing_function to figure out which parameters are changed and which one's aren't. (particularly in the case of
Disagree strongly all you want, but I only use pointers to indicate optional arguments and to pass references (general meaning of the word) to objects that are expected to outlive the object to which they are given (usually in the ctor). In the former case, the argument may be null so I check for that case. In the latter, I often use RCSPs, but not always.
I don't use non-const reference parameters often (and when I do they are always the first argument(s)). I find they work intuitively. You see, such functions always indicate, by their very name, that they are providing a value, so the name quite reasonably documents the output parameter.
Using pointers in this context would be counterintuitive to me.
Ultimately, someone will be disappointed.
OK, how about this syntax, to make it much more clear what is being returned (and, at the same time, to reduce the verbiage):
desc.add_options()
...
(param("magic|value|magic value for the program") >> magic)
(param("val||some value with a default", defaultValue) >> val)
...
;I've combined all 3 strings into one argument. Why have 3? It just takes up space. The 3 strings are separated by | (or pick a better seperator char). param() is a template function. I haven't tested this, but it seems like it could be made to work...
- Chuck
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