Very strange problem with comparing floating point numbers

[monarch_dodra]

On Sunday, 30 September 2012 at 01:29:24 UTC, Ivan Agafonov wrote:
> // Tell me about this sutation, may be it is a bug?
>
> [SNIP]
> 	// all of this fails!!!
> 	assert (a.length == a.length); // This is really shocking
> 	assert (a.length == a3.length);
> [SNIP]

This is just a fact of life regarding how floating point types 
work. Here is a well documented explanation. It pertains to C++, 
but applies.

http://www.parashift.com/c++-faq/floating-point-arith2.html

As a rule of thumb, NEVER use opEqual with floating point types 
aniways. You need to use some sort of comparison with leway for 
error, such as std.math.approxEqual.