On Tuesday 2014-12-23 08:36 -0800, Eric Rescorla wrote: > > Why not pass the raw pointer to the function? > > > My general theory is that smart pointers, once boxed, should never be > unboxed. > The major arguments I see for unboxing is performance, but if you pass a > ref, > then you don't have the increment/decrement cycle. > > > > > That's what we do in most of the places in the code. > > > > Yes, I think this is unwise.
Our convention has always been to pass raw pointers, generally with the assumption that the caller is expected to ensure the pointer lives across the function call. Passing references to smart pointers doesn't work if you need implicit conversions from derived class to base class (e.g., if the function takes Base*, and the caller has nsRefPtr<Derived>), which is pretty important in many areas of our codebase. Passing smart pointers (non-references) would cause tons of extra reference count traffic, which is particularly problematic when the reference-counting functions are virtual and/or threadsafe. -David -- 𝄞 L. David Baron http://dbaron.org/ 𝄂 𝄢 Mozilla https://www.mozilla.org/ 𝄂 Before I built a wall I'd ask to know What I was walling in or walling out, And to whom I was like to give offense. - Robert Frost, Mending Wall (1914)
signature.asc
Description: Digital signature
_______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
