Re: [boost] [Boost-bugs] [ boost-Bugs-1315712 ] Addingboost::is_complex to type_traits.hpp

From: Neal Becker (ndbecker2_at_[hidden])
Date: 2005-10-07 11:49:32

John Maddock wrote:

>> Uh, where is it?
> 
> It was posted to the boost-users list.  Implementation is utterly trivial
> anyway.
> 
>> There are a number of useful things to go with complex.  Here is
>> another.
>>
>> It is common to need the scalar type that corresponds to a numeric
>> type, whether that type is complex or scalar.  For example, the type
>> returned by abs.  Implementation is pretty trivial:
> 
> Interesting, and good point.
> 
> OK, is there any objection to is_complex being added, what about Neal's
> trait (and what to call it if it is added, "scalar" maybe?).
> 

I propose a collection of complex utilities.  This would include:

1) is_complex
2) scalar
3) A collection of iterator adapters:
  3.1) Transform complex sequence to scalar (yield alternating real/imag
parts)
  3.2) Inverse of 3.1
  3.3) Pick off real part of complex
  3.4) Pick off imag part of complex
  3.5) zip 2 scalar sequences into complex sequence

I have code based on boost iterator adapter for all the above.