approxEqual() has fooled me for a long time...

[Walter Bright]

bearophile wrote:
> Andrei Alexandrescu:
> 
>> 2. Find a more intuitive interface for feqrel, i.e. using decimal digits 
>> for precision etc. The definition in std.math: "the number of mantissa bits
>> which are equal in x and y" loses 90% of the readership at the word 
>> "mantissa". You want something intuitive that people can immediately 
>> picture.
> 
> If you assume that a reader of those docs may know what the FP mantissa is,
> then the solution is not to remove the word "mantissa" from there, but to add
> a link to Wikipedia page, or/and to just show an image like: 
> http://en.wikipedia.org/wiki/File:IEEE_754_Double_Floating_Point_Format.svg 
> If you want to use a function about floating point approximations you need to
> know how a FP is represented.

The image doesn't use the word "mantissa" !

Though I do agree that the docs, where appropriate, should have links to 
explanatory definitions. There are some in the Phobos docs already.