On Thu, Dec 4, 2014 at 11:28 AM, Robert O'Callahan <rob...@ocallahan.org> wrote:
> On Thu, Dec 4, 2014 at 12:35 PM, Seth Fowler <s...@mozilla.com> wrote: > > > I’d like to change the coding style guide to let us make out-params more > > obvious by using an ‘o’ prefix for their name instead of an ‘a’. For > > example, > > > > nsresult Modify(int aCount, size_t aSize, char* oResult); > > > > This will make it clear just from the declaration of a function or method > > which parameters are out-params. XPCOM requires us to use out-params a > lot, > > and I’ve found that determining when it’s happening often requires me to > > look at the code for the method, especially since we frequently use > pointer > > arguments for efficiency or because the argument is optional. > > > > Seems to me like a substantial gain in readability for little or no cost. > > > > I think this would be a slight improvement but the place where I really > want out-parameters to be visible is at the caller, not the callee. > I guess, to make it clear at caller side, and force the compiler to check it as much as possible, the best way would be having a template class e.g. Out<> which holds a reference to the target variable, and giving it proper implicit conversion, e.g. Out<T> can be implicitly converted to T& but not inversely. With that, I guess we can use it directly in new code, and the usage in caller will be compatible with the existing functions. Might be something like this: https://gist.github.com/upsuper/322bde839f3552ff7e3b - Xidorn _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
