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digitalmars.D.learn - convert *void to void[]

reply gabrielsylar <noreply email.com> writes:
can anybody please tell me how to properly convert from void* to void[]
as the code below?

void[] get_bytes(int n) { return sqlite3_column_blob(stmt, n); }
May 06 2009
next sibling parent reply TSalm <TSalm free.fr> writes:
Le Wed, 06 May 2009 10:17:47 +0200, gabrielsylar <noreply email.com> a  
écrit:


 can anybody please tell me how to properly convert from void* to void[]
 as the code below?

 void[] get_bytes(int n) { return sqlite3_column_blob(stmt, n); }



Something like could works :
   return *( cast(void[]*) sqlite3_column_blob(stmt, n) ) ;
May 06 2009
parent TSalm <TSalm free.fr> writes:
Le Wed, 06 May 2009 10:33:33 +0200, TSalm <TSalm free.fr> a écrit:


 Le Wed, 06 May 2009 10:17:47 +0200, gabrielsylar <noreply email.com> a  
 écrit:


 can anybody please tell me how to properly convert from void* to void[]
 as the code below?

 void[] get_bytes(int n) { return sqlite3_column_blob(stmt, n); }



 Something like could works :
    return *( cast(void[]*) sqlite3_column_blob(stmt, n) ) ;




Forget my example, it's wrong.
Sorry.
May 06 2009
prev sibling next sibling parent Robert Fraser <fraserofthenight gmail.com> writes:
gabrielsylar wrote:

 can anybody please tell me how to properly convert from void* to void[]
 as the code below?
 
 void[] get_bytes(int n) { return sqlite3_column_blob(stmt, n); }



void[] has a length, so you have to know the length. Assuming the length 
is n... Maybe try something like this (untested):

struct DynArray
{
     public void* ptr;
     public size_t length;
     public T[] toArray(T)() { return cast(T[]) cast(void*) (*this); }
}

void[] get_bytes(int n)
{
     return DynArray(sqlite3_column_blob(stmt, n), n).toArray!(void);
}
May 06 2009
prev sibling next sibling parent John C <johnch_atms hotmail.com> writes:
gabrielsylar Wrote:


 can anybody please tell me how to properly convert from void* to void[]
 as the code below?
 
 void[] get_bytes(int n) { return sqlite3_column_blob(stmt, n); }



return sqlite3_column_blob(stmt, n)[0 .. n];
May 06 2009
prev sibling parent reply downs <default_357-line yahoo.de> writes:
gabrielsylar wrote:

 can anybody please tell me how to properly convert from void* to void[]
 as the code below?
 
 void[] get_bytes(int n) { return sqlite3_column_blob(stmt, n); }



In unrelated matters: if you're writing a sqlite3 binding, take a look at
tools.sqlite3. :)

http://dsource.org/projects/scrapple/browser/trunk/tools/tools/sqlite3.d
May 06 2009
parent gabrielsylar <noreply email.com> writes:
downs Wrote:


 gabrielsylar wrote:

 can anybody please tell me how to properly convert from void* to void[]
 as the code below?
 
 void[] get_bytes(int n) { return sqlite3_column_blob(stmt, n); }



 In unrelated matters: if you're writing a sqlite3 binding, take a look at
tools.sqlite3. :)
 
 http://dsource.org/projects/scrapple/browser/trunk/tools/tools/sqlite3.d



thanks, but im writing my own simple wrapper around sqlite3.dll(so) dynamic
loadable library
May 06 2009