getCommandInfoFor

import std.typecons : Nullable;

@Command("test", "doe")
static struct C
{
    @CommandNamedArg("abc", "123") string arg;
    @CommandPositionalArg(20, "ray", "me") @CommandArgGroup("nam") Nullable!bool pos;
    @CommandNamedArg @(CommandArgAction.count) int b;
}

enum info = getCommandInfoFor!(C, ArgBinder!());
static assert(info.pattern.matchSpaceless("test"));
static assert(info.description == "doe");
static assert(info.namedArgs.length == 2);
static assert(info.positionalArgs.length == 1);

static assert(info.namedArgs[0].identifier == "arg");
static assert(info.namedArgs[0].uda.pattern.matchSpaceless("abc"));
static assert(info.namedArgs[0].action == CommandArgAction.default_);
static assert(info.namedArgs[0].group == CommandArgGroup.init);
static assert(info.namedArgs[0].existence == CommandArgExistence.default_);
static assert(info.namedArgs[0].parseScheme == CommandArgParseScheme.default_);

static assert(info.positionalArgs[0].identifier == "pos");
static assert(info.positionalArgs[0].uda.position == 20);
static assert(info.positionalArgs[0].action == CommandArgAction.default_);
static assert(info.positionalArgs[0].group.name == "nam");
static assert(info.positionalArgs[0].existence == CommandArgExistence.optional);
static assert(info.positionalArgs[0].parseScheme == CommandArgParseScheme.bool_);

static assert(info.namedArgs[1].action == CommandArgAction.count);