SysTime in a Struct

[albatroz]

Hi Ali,

only today I had the time to implement your suggestion it's 
working now has expected.

Thank you for your patience, also thank you for the work 
translating such a good D book to English.


On Friday, 2 March 2012 at 00:00:10 UTC, Ali Çehreli wrote:
> On 03/01/2012 03:46 PM, albatroz wrote:
>
> > Hi Ali, just tring to define a type that holds this
> information. It was
> > just an attempt to create a type DateTime with the values
> from the known
> > strings, I thought it was possible to create the definition
> directly in
> > the Struct, with no need for an external function.
> > edate and etime are strings that I will read in to the
> struct, but for
> > operations with time and dates I need to create/define a
> DateTime type.
>
> From that description, it looks like you can hold edate etc. as 
> members and produce SysTime as needed. The following 
> demonstrates how to convert preEv to SysTime by opCast 
> implicitly and by sys_time explicitly:
>
> import std.stdio;
> import std.conv;
> import std.datetime;
>
> struct preEv
> {
>     string edate; //010112
>     string etime; //00:00:00
>     string etext; //
>
>     SysTime opCast(T : SysTime)() const
>     {
>         return SysTime(DateTime(
>                            Clock.currTime.year,
>                            to!int(this.edate[2..4]),
>                            to!int(this.edate[0..2]),
>                            to!int(etime[0..2]),
>                            to!int(etime[3..5]),
>                            to!int(etime[6..8])));
>     }
>
>     SysTime sys_time() const @property
>     {
>         return to!SysTime(this);
>     }
> }
>
> void main()
> {
>     auto pe = preEv("010312", "15:53:00", "The event");
>
>     // Explicit conversion
>     auto st0 = to!SysTime(pe);
>     writeln(st0);
>
>     // Casting
>     auto st1 = cast(SysTime)(pe);
>     writeln(st1);
>
>     // As a property
>     auto st2 = pe.sys_time;
>     writeln(st2);
> }
>
> If you think that you need to cache SysTime in the object 
> itself, you can do that for example in opCast.
>
> On the other hand, if all you need to store is SysTime and 
> etext, then you need to create SysTime in the constructor:
>
> import std.stdio;
> import std.conv;
> import std.datetime;
>
> struct preEv
> {
>     SysTime time;
>     string etext;
>
>     this (string edate, string etime, string etext)
>     {
>         this.time = SysTime(DateTime(
>                                 Clock.currTime.year,
>                                 to!int(edate[2..4]),
>                                 to!int(edate[0..2]),
>                                 to!int(etime[0..2]),
>                                 to!int(etime[3..5]),
>                                 to!int(etime[6..8])));
>         this.etext = etext;
>     }
> }
>
> void main()
> {
>     auto pe = preEv("010312", "15:53:00", "The event");
>
>     writeln(pe.time);
> }
>
> Ali