import std.stdio;
import std.file;


void main(string[] args)
{
	if (args.length != 2)
	{
		writeln("usage: ./app <path-to-file>");
		return;
	}

	if (!exists!(args[1]))
	{
		writefln("fatal error: %s doesn't exist", args[1]);
	}
}

Line 13 (if (!exists!(args[1]))) produces error:

'app.d(13): Error: variable args cannot be read at compile time'

With 'dmd -run app.d' compilation command. I've seen another Stackoverflow post with a similar issue (https://stackoverflow.com/questions/39920780/variable-i-cannot-be-read-at-compile-time) but I don't believe it to be related.

Any help?

On Sunday, 10 December 2017 at 15:28:19 UTC, Unazed Spectaculum wrote:
> 	if (!exists!(args[1]))

That should be `!exists(args[1])`. You had an extra ! in there by the (.


Generally speaking, when there's a "cannot be read at compile time", it is because something is initialized in a static context and/or there's an extra ! in the arg list to get rid of.

On Sunday, 10 December 2017 at 15:46:57 UTC, Adam D. Ruppe wrote:
> On Sunday, 10 December 2017 at 15:28:19 UTC, Unazed Spectaculum wrote:
>> 	if (!exists!(args[1]))
>
> That should be `!exists(args[1])`. You had an extra ! in there by the (.
>
>
> Generally speaking, when there's a "cannot be read at compile time", it is because something is initialized in a static context and/or there's an extra ! in the arg list to get rid of.

Thanks! That fixed it. I'll take it into account whenever I see any other future errors like it.