Templates and writing variable number of arguments
ted via Digitalmars-d-learn
digitalmars-d-learn at puremagic.com
Sun Aug 23 14:46:09 PDT 2015
try replacing:
final void output(T)(string text, T params...) const {
with
final void output(T...)(string text, T params) const {
Andre Polykanine via Digitalmars-d-learn wrote:
> Hi everyone,
> It's me again.
> Now I'm struggling with the `output` member function which should
> output a string either to stdout or to a file, depending on the
> parameter.
> However, I would like it to work like `writefln` with variable number
> of arguments:
> output("Hello %s!", "world"); // should be OK
> output("%s %s: %s %d times", "I", "say", "Hello world!", 500); //
> Should also be OK
>
> Here is my code:
>
> final void output(T)(string text, T params...) const {
> if (this.outFile == "") {
> writefln(text, params);
> } else { // Output to a file
> auto f = File(this.outFile, "w");
> try {
> f.writefln(text, params);
> } catch(Exception e) {
> writefln("Unable to write to %s: %s",
> this.outFile, e.msg);
> }
> }
> }
>
> And the compiler says it can't deduce the type of arguments.
> What am I doing wrong here?
> Maybe, I don't need such a function and all and there is a way to make
> it more elegant?
> Thanks!
>
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