[boost] Re: Insufficient significant digits using lexical_cast

From: Daryle Walker (dwalker07_at_[hidden])
Date: 2003-08-18 01:05:01

On Sunday, August 17, 2003, at 10:33 PM, Paul A. Bristow wrote:

[SNIP]
> But you are right that it would be better to check that 
> numeric_limits::digits exists and isn't something silly before using 
> the formula.  With all the built-in floating point types it should be 
> fine, and for other (well) User defined floating point types too.  (I 
> will look at this).
[TRUNCATE]

I think you need to check numeric_limits::radix since your algorithm 
had a base-2-to-10 conversion (the type may not actually be binary!).  
The algorithm was based off a paper about IEEE-754; if IEEE-754 is a 
requirement, you may have to check for that too (via 
numeric_limits::is_iec559).  Remember that even the built-in 
floating-point types aren't guaranteed to match IEEE-754!

Daryle