This code:

	bool time;
	string fileIn;
	string fileOut;

	auto helpInformation = getopt(
		args,
		"time", "Show timing information", &time,
		"i|input", "Input file (defaults to stdin)", &fileIn,
		"o|output", "Output file (defaults to stdout)", &fileOut
	);

	if (helpInformation.helpWanted)
	{
		defaultGetoptPrinter("ECMAScript 5 minifier.\n\nUsage:\t"~baseName(args[0])~" [OPTIONS]\n\nOptions:\n", helpInformation.options);
		return 1;
	}

on gdc 5.3.0-1 Gives me:

/usr/include/dlang/gdc/std/getopt.d:547:36: error: cannot modify immutable expression *cast(immutable(char)*)receiver
                 if (incremental) ++*receiver;
                                    ^
/usr/include/dlang/gdc/std/getopt.d:548:22: error: cannot modify immutable expression *cast(immutable(char)*)receiver
                 else *receiver = to!(typeof(*receiver))(val);
                      ^
/usr/include/dlang/gdc/std/getopt.d:441:25: error: template instance std.getopt.handleOption!string error instantiating
             handleOption(option, receiver, args, cfg, incremental);
                         ^
/usr/include/dlang/gdc/std/getopt.d:392:22: note: instantiated from here: getoptImpl!(string, string, bool*, string, string, string*, string, string, string*)
     return getoptImpl(args, cfg, opts);
                      ^
source/app.d:24:31: note: instantiated from here: getopt!(string, string, bool*, string, string, string*, string, string, string*)
  auto helpInformation = getopt(
                               ^
/usr/include/dlang/gdc/std/getopt.d:433:33: error: array index [1] is outside array bounds [0 .. 1]
             auto receiver = opts[1];
                                 ^
/usr/include/dlang/gdc/std/getopt.d:442:46: error: string slice [2 .. 1] is out of bounds
             return getoptImpl(args, cfg, opts[2 .. $]);
                                              ^
/usr/include/dlang/gdc/std/getopt.d:442:13: error: cannot return non-void from void function
             return getoptImpl(args, cfg, opts[2 .. $]);
             ^
/usr/include/dlang/gdc/std/getopt.d:442:30: error: template instance std.getopt.getoptImpl!(string*) error instantiating
             return getoptImpl(args, cfg, opts[2 .. $]);
                              ^
/usr/include/dlang/gdc/std/getopt.d:442:30: note: instantiated from here: getoptImpl!(string, string, string*)
             return getoptImpl(args, cfg, opts[2 .. $]);
                              ^
/usr/include/dlang/gdc/std/getopt.d:442:30: note: instantiated from here: getoptImpl!(string, string*, string, string, string*)
             return getoptImpl(args, cfg, opts[2 .. $]);
                              ^
/usr/include/dlang/gdc/std/getopt.d:442:30: note: instantiated from here: getoptImpl!(bool*, string, string, string*, string, string, string*)
             return getoptImpl(args, cfg, opts[2 .. $]);
                              ^
/usr/include/dlang/gdc/std/getopt.d:392:22: note: instantiated from here: getoptImpl!(string, string, bool*, string, string, string*, string, string, string*)
     return getoptImpl(args, cfg, opts);
                      ^
source/app.d:24:31: note: instantiated from here: getopt!(string, string, bool*, string, string, string*, string, string, string*)
  auto helpInformation = getopt(
                               ^
/usr/include/dlang/gdc/std/getopt.d:442:13: error: cannot return non-void from void function
             return getoptImpl(args, cfg, opts[2 .. $]);
             ^
/usr/include/dlang/gdc/std/getopt.d:442:13: error: cannot return non-void from void function
             return getoptImpl(args, cfg, opts[2 .. $]);
             ^
/usr/include/dlang/gdc/std/getopt.d:442:13: error: cannot return non-void from void function
             return getoptImpl(args, cfg, opts[2 .. $]);
             ^
/usr/include/dlang/gdc/std/getopt.d:442:13: error: cannot return non-void from void function
             return getoptImpl(args, cfg, opts[2 .. $]);
             ^
/usr/include/dlang/gdc/std/getopt.d:392:5: error: cannot return non-void from void function
     return getoptImpl(args, cfg, opts);
     ^
source/app.d:33:3: error: undefined identifier defaultGetoptPrinter
   defaultGetoptPrinter("ECMAScript 5 minifier.\n\nUsage:\t"~baseName(args[0])~" [OPTIONS]\n\nOptions:\n", helpInformation.options);
   ^

Am Thu, 21 Jan 2016 12:06:18 +0000
schrieb Sebastiaan Koppe <mail@skoppe.eu>:

> This code:
> 
> 	bool time;
> 	string fileIn;
> 	string fileOut;
> 
> 	auto helpInformation = getopt(
> 		args,
> 		"time", "Show timing information", &time,
> 		"i|input", "Input file (defaults to stdin)", &fileIn,
> 		"o|output", "Output file (defaults to stdout)",
> &fileOut );
> 
> 	if (helpInformation.helpWanted)
> 	{
> 		defaultGetoptPrinter("ECMAScript 5
> minifier.\n\nUsage:\t"~baseName(args[0])~"
> [OPTIONS]\n\nOptions:\n", helpInformation.options);
> 		return 1;
> 	}
> 

defaultGetoptPrinter is not yet available in the phobos version used by GDC. GDC uses phobos version 2.066, defaultGetoptPrinter was added in 2.067.

On Friday, 22 January 2016 at 10:06:01 UTC, Johannes Pfau wrote:
> defaultGetoptPrinter is not yet available in the phobos version used by GDC. GDC uses phobos version 2.066, defaultGetoptPrinter was added in 2.067.

Thanks. I never know which version of this supports which version of that. Any easy way of checking this? I mean, how can I tell that gdc 5.3.0-1 supports phobos 2.066?

I reckon other people run into these errors as well, and it would be nice if there was a way of checking whether a function is supported in gdc/ldc x.x.x Hmm. Sounds like a nice project with git, libdparse and vibe.

What about the other errors though?

Am Fri, 22 Jan 2016 11:32:30 +0000
schrieb Sebastiaan Koppe <mail@skoppe.eu>:

> On Friday, 22 January 2016 at 10:06:01 UTC, Johannes Pfau wrote:
> > defaultGetoptPrinter is not yet available in the phobos version used by GDC. GDC uses phobos version 2.066, defaultGetoptPrinter was added in 2.067.
> 
> Thanks. I never know which version of this supports which version of that. Any easy way of checking this? I mean, how can I tell that gdc 5.3.0-1 supports phobos 2.066?
> 

The best way is running this code snippet:
---------------------------------------------------
import std.compiler;
import std.stdio;

void main()
{
    writefln("%s %s %s.%s (D%s)", name, vendor,
        version_major,
        version_minor, D_major);
}
---------------------------------------------------
You can also have a look at the std.compiler implementation if you want to use the __VERSION__ and __VENDOR__ variables directly.

> I reckon other people run into these errors as well, and it would be nice if there was a way of checking whether a function is supported in gdc/ldc x.x.x Hmm. Sounds like a nice project with git, libdparse and vibe.

Yes, this is really a common problem. I'd say the simplest way to check is trying to compile the code with the matching DMD version (e.g. 2.066.1).

> What about the other errors though?

Same reason. The old getopt code can't handle the help strings and therefore produces these error messages. This works:

---------------------------------------------------
import std.getopt;
void main(string[] args)
{
	bool time;
	string fileIn;
	string fileOut;

	getopt(
		args,
		"time", &time,
		"i|input", &fileIn,
		"o|output", &fileOut
	);
}

On Friday, 22 January 2016 at 13:03:58 UTC, Johannes Pfau wrote:
> Am Fri, 22 Jan 2016 11:32:30 +0000
> schrieb Sebastiaan Koppe <mail@skoppe.eu>:
>> Thanks. I never know which version of this supports which version of that. Any easy way of checking this? I mean, how can I tell that gdc 5.3.0-1 supports phobos 2.066?
>> 
> The best way is running this code snippet:
> ---------------------------------------------------
> import std.compiler;
> import std.stdio;
>
> void main()
> {
>     writefln("%s %s %s.%s (D%s)", name, vendor,
>         version_major,
>         version_minor, D_major);
> }
> ---------------------------------------------------

Why doesn't gdc emit this when called with `--version`?

> Yes, this is really a common problem. I'd say the simplest way to check is trying to compile the code with the matching DMD version (e.g. 2.066.1).

When I have nothing to do I might setup a service that tells you in which version a symbol was introduced.

>> What about the other errors though?
>
> Same reason. The old getopt code can't handle the help strings and therefore produces these error messages.

I see, I was mislead due to the errors being in the std code.