How are _variant_t accessor function used?

Question

0.00/5 (No votes)

See more:

I am writing a database access class that will eventually return a _variant_t as result.I need to extract the returned data.Initially I intended to cast it to the desired type but ITS learnt that it insn't neccessary all I ought to do is use the accessor.

Please how does one use an accessor.
Id appreciate it if I am shown at leasd a line of code that accesses a variant and assigninv the outcome of the assessing to a variable.

See associated question here:

http://www.codeproject.com/Questions/722847/Can-the-void-pointer-returned-by-SafeArrayGetElemeI

Posted 8-Feb-14 2:23am

Gbenbam

Add a Solution

Comments

[no name] 8-Feb-14 20:13pm

I think you mean extractor. This may help http://flylib.com/books/en/1.22.1.157/1/

2 solutions

Solution 1

_variant_t is defined in comutil.h for anyone to see.

http://msdn.microsoft.com/en-us/library/ew0bcz27.aspx[^]

You may need to use a typecast to get the appropriate extractor.

Posted 10-Feb-14 11:20am

bling

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

«_Superman_» · Accepted Answer · 2014-02-10T20:06:00

Solution 2

Extractors in the _variant_t class are nothing but overloaded operators like short, long, float, double etc. that finally end up calling the VariantChangeType API.

The syntax would be the same as a type cast -

_variant_t var(25.4);

short s = (short)var;
long l = (long)var;

OR

short s = short(var);
long l = long(var);

Posted 10-Feb-14 20:06pm

«_Superman_»

Comments

Gbenbam 11-Feb-14 2:19am

This is so mightily clarifying.Thank you so much.Thanks a trillion times.