Le 01/09/11 03:15, Emil Dotchevski a écrit :
On Wed, Aug 31, 2011 at 5:45 PM, Gordon Woodhull<gordon@woodhull.com> wrote:
On Aug 31, 2011, at 5:11 PM, Emil Dotchevski wrote:
On Wed, Aug 31, 2011 at 1:13 PM, Gordon Woodhull<gordon@woodhull.com> wrote:
On Aug 31, 2011, at 3:01 PM, Emil Dotchevski wrote: In other words, the ugliness is confined to the definition of conversions and doesn't spill over into their use. But the conversion definitions do get to benefit from ADL... actually I don't see how a conversion library could benefit from implicit conversions of the target type, but I might be missing something. My point about ADL doesn't apply since the<> syntax is limited only to the point of the user calling convert_to, that is, as long as explicit_convert_to still uses ADL and it is not required to be a template, all is good.
When I mentioned implicit conversions, I meant of the source type. Assuming the internals of convert_to<> do not require the actual conversion to be handled by templates, This is the case. The behavior is similar to the obe of boost::swap.
boost::conversion::explicit_convert_to<Target>(source) calls explicit_convert_to(source, conversion::type_tag<Target>()) which could be overloaded.
it is possible to define a small set of non-template overloads to handle a much larger set of input types that are already part of a carefully designed implicit conversion framework. I don't know IIUC, when you use implicit, are you refering to predefined by the library? If yes, which conversion do you think that should belong to this set? If templates were required, the call to explicit_convert_to could instantiate a template instead of resorting to implicit conversion. I'm not saying that one is better than the other, only that both should be supported.
Here I'm lost. Best, Vicente