floating point conversion

[Famous via Digitalmars-d-learn]

I have compiled some cases at

  http://dpaste.dzfl.pl/5611b8bce8e3

This implies that floating-point constants do not have fixed but 
minimum precision. Particularly, the literal 1.23 describes a 
floating-point value with either double or real precision 
depending on what it is compared to.

This seems to comply with

  http://dlang.org/float.html