[Liblas-devel] HasColor() and HasTime() removed from Schema class public interface

[Trudgett, David]

Hello, Howard,

> I have changed this again to no longer throw an exception 
> if nothing is found.  Instead, as suggested by Mateusz, 
> the Dimension is wrapped in a boost::optional that may be null.

Yes, that sounds reasonable. :-)

I've been away on holidays, in case you're wondering about the delayed
response... ;-)

Regards,
David Trudgett
 





 
-----Original Message-----
From: Howard Butler [mailto:hobu.inc at gmail.com] 
Sent: Friday, 24 December 2010 05:44
To: Trudgett, David
Cc: liblas-devel at lists.osgeo.org
Subject: Re: [Liblas-devel] HasColor() and HasTime() removed from Schema
class public interface


On Dec 19, 2010, at 8:38 PM, Howard Butler wrote:

> The proper way to ask for HasColor or HasTime now is to ask the schema
if the color or time dimensions exist.
> 
> bool bColorExists = false;
> try {
> 
> 	liblas::Dimension const& red = schema.GetDimension("Red");
> 	liblas::Dimension const& green = schema.GetDimension("Green");
> 	liblas::Dimension const& blue = schema.GetDimension("Blue");
> 	bColorExists = true;
> 
> } catch (std::runtime_error const&)
> {
> }

David,

I have changed this again to no longer throw an exception if nothing is
found.  Instead, as suggested by Mateusz, the Dimension is wrapped in a
boost::optional that may be null.

boost::optional< Dimension const& > red = schema.GetDimension("Red");
boost::optional< Dimension const& > green =
schema.GetDimension("Green");
boost::optional< Dimension const& > blue = schema.GetDimension("Blue");

if (red && green && blue)
    bColorExists = true;

A boost::optional can be dereferenced to get the const &.  For example,

red->GetName();  

Thanks for the feedback.  I think this is better :)

Howard
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