std.stream example

Gide Nwawudu gide at btinternet.com
Mon Apr 28 15:44:18 PDT 2008


On Mon, 28 Apr 2008 13:36:18 +0000 (UTC), "Me Here"
<p9e883002 at sneakemail.com> wrote:

>
>I just tried to compile the following example ffrom the std.stream docs:
>
>import std.stdio;
>import std.stream;
>
>int main (char[][] args) {
>    
>    Stream file = new BufferedFile( "myfile" );
>    foreach( ulong n, string line; file ) {
>        writefln( "line %d: %s", n,line );
>    }
>    file.close();
>    return 0;
>}
>
>I'm getting:
>
>
>fhash.d(31): function std.stream.Stream.opApply (int delegate(ref char[] line)) 
>does not match parameter types (int delegate(ref ulong __applyArg0, ref invariant(char)[] __applyArg1))
>
>fhash.d(31): Error: cannot implicitly convert expression (__foreachbody15) 
>of type int delegate(ref ulong __applyArg0, ref invariant(char)[] __applyArg1) 
>to int delegate(ref ulong n, ref wchar[] line)
>
>Have I got my libraries screwed up? 
>Or c&p the example incorrectly?
>Or is the example just out of date or otherwise screwed?
>
>Cheers, b.

> Or is the example just out of date  ...
Example is wrong.

D1 declares a string as char[], D2 declares it as invariant(char)[].
It does not compile because the line variable being passed to
Stream.onApply should be mutable.

So foreach( ulong n, string line; file )  changes to:

foreach( ulong n, char[] line; file )  
- or - 
foreach( ulong n, ref char[] line; file ) 


Gide




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