There is "isFloatingPointType!T" to find out whether type T is one of the floating point types but I could not find anything equivalent for complex numbers (cdouble, cfloat, creal) in Phobos 2.066 (which I installed with MacPorts for the record). Am I missing something?

My goal was to detect types suitable as scalars in a linear algebra context. I had to do it by hand:

enum bool supportedScalar(T) = is(ScalarTypeOf!T) && !isAggregateType!T;

private {
  alias ScalarTypeList = TypeTuple!(float, double, real,
                                    cfloat, cdouble, creal);
  template ScalarTypeOf(T) {
      static if (is(AliasThisTypeOf!T AT) && !is(AT[] == AT))
          alias X = ScalarTypeOf!AT;
      else
          alias X = OriginalType!T;

      static if (staticIndexOf!(Unqual!X, ScalarTypeList) >= 0)
          alias ScalarTypeOf = X;
      else
          static assert(0, T.stringof~" is not a floating point type");
  }
}

I forgot to mention the obvious: I simply parroted the code in std.traits!

On Wednesday, 14 January 2015 at 13:38:05 UTC, Luc Bourhis wrote:
> There is "isFloatingPointType!T" to find out whether type T is one of the floating point types but I could not find anything equivalent for complex numbers (cdouble, cfloat, creal) in Phobos 2.066 (which I installed with MacPorts for the record). Am I missing something?
>
> My goal was to detect types suitable as scalars in a linear algebra context. I had to do it by hand:
>
> enum bool supportedScalar(T) = is(ScalarTypeOf!T) && !isAggregateType!T;
>
> private {
>   alias ScalarTypeList = TypeTuple!(float, double, real,
>                                     cfloat, cdouble, creal);
>   template ScalarTypeOf(T) {
>       static if (is(AliasThisTypeOf!T AT) && !is(AT[] == AT))
>           alias X = ScalarTypeOf!AT;
>       else
>           alias X = OriginalType!T;
>
>       static if (staticIndexOf!(Unqual!X, ScalarTypeList) >= 0)
>           alias ScalarTypeOf = X;
>       else
>           static assert(0, T.stringof~" is not a floating point type");
>   }
> }

It doesn't answer your question as such, but you should take a look at:
http://dlang.org/phobos/std_complex.html

> It doesn't answer your question as such, but you should take a look at:
> http://dlang.org/phobos/std_complex.html

The planned obsolescence of cdouble and consort is another issue I wanted to raise actually but better do it in a dedicated thread.