[fpc-pascal] Re: Variant vs Pointer
md at delfire.net
Fri Mar 2 20:37:34 CET 2012
On Fri, Mar 2, 2012 at 1:02 PM, <michael.vancanneyt at wisa.be> wrote:
> On Fri, 2 Mar 2012, Marcos Douglas wrote:
>> On Wed, Feb 29, 2012 at 10:38 PM, Marcos Douglas <md at delfire.net> wrote:
>>> The TField class have the FValueBuffer: Pointer attribute and have
>>> also SetData(Buffer: Pointer,...) method that all T***Field subclasses
>>> use to set themselves.
>>> The methods AsInteger, AsString, etc use FValueBuffer to convert in an
>>> especific type. So, FValueBuffer could be anything.
>>> My question is:
>>> What would be the difference in performance if FValueBuffer were a
>>> Variant type?
>>> Marcos Douglas
>> Nobody knows?
>> I need implements a similar structure but I need know if the use of
>> Variant have very cost.
> It has a cost.
> The reason for using a buffer in tdataset is that a record's data normally
> is located in one continuous buffer, from which a value is picked from the
> right spot (including strings) You can't have that with variants.
So, if I will have a class like a TParam, that have FValue: Variant
attribute, Would you change the implementation to not use Variant?
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