Russell Hind wrote:
Edward Diener wrote:
The one area where C++ is weaker than other languages for design time UI, and component, development is in its lack of a general run-time reflection mechanism. That is the only area which I see that is holding it back.
A solution I've read about that I like to solve this is a separate 'pre-processor' that can pass your current project and look for certain members/member-functions and generate code to build up the appropriate required run-time information
(e.g. it could recognise the '__published:' section of Borland's VCL classes and generate the code containg the list of members in that section which would be accessible at runtime)
I'm sure this could be done in a compiler independent way as it would be parsing C++ code and generating C++ code to then be compiled by your compiler of choice.
I can't remember where I first read about this idea but perhaps someone else has more information.
.NET actually adds code to the source files using a component, based on design time decisions by the programmer, but it uses .NET reflection on the compiled component in order to do so. What you are suggesting is that one must parse component source code at design time in order to add code to the source which uses that component. This presupposes that the source code for all components used at design time must be available. Sorry if I find that a disagreeable thought. C++ Builder, as I am sure you know, actually uses reflection at run-time to create the correct values for properties and events handlers, without altering the source one sees for the user of the component. I actually feel this is cleaner. However both .NET and C++ Builder use run-time reflection of components and do not need component source in order to set up the correct values. Having to parse C++ code at design-time may be doable but I do not think it is a good way of doing things. Besides needing the source for the component, it is always possible that the source is incorrect and has errors. When run-time reflection can actually be used on the compiled component, there is no need for component source and the compiled component is always correct. For these reasons I much prefer a guaranteed run-time reflection mechanism rather than a source code parser for design time RAD developement. In the area of run-time reflection, Java, .NET, and Python have an obvious advantage over C++. Other than run-time reflection, I find C++ generally equal to, or better, than those other languages and environments, although I have a great fondness for Python nonetheless.