LibCore: Add new String variants to ArgsParser

This commit adds the ability to use the String class with `add_option`
and `add_positional_argument`.

This should help with the transition away from DeprecatedString.

Userland/Libraries/LibCore/ArgsParser.cpp

@@ -430,6 +430,27 @@ void ArgsParser::add_option(DeprecatedString& value, char const* help_string, ch
     add_option(move(option));
 }
 
+void ArgsParser::add_option(String& value, char const* help_string, char const* long_name, char short_name, char const* value_name, OptionHideMode hide_mode)
+{
+    Option option {
+        OptionArgumentMode::Required,
+        help_string,
+        long_name,
+        short_name,
+        value_name,
+        [&value](StringView s) {
+            auto value_or_error = String::from_utf8(s);
+            if (value_or_error.is_error())
+                return false;
+
+            value = value_or_error.release_value();
+            return true;
+        },
+        hide_mode,
+    };
+    add_option(move(option));
+}
+
 void ArgsParser::add_option(StringView& value, char const* help_string, char const* long_name, char short_name, char const* value_name, OptionHideMode hide_mode)
 {
     Option option {
@@ -610,6 +631,25 @@ void ArgsParser::add_positional_argument(StringView& value, char const* help_str
     add_positional_argument(move(arg));
 }
 
+void ArgsParser::add_positional_argument(String& value, char const* help_string, char const* name, Required required)
+{
+    Arg arg {
+        help_string,
+        name,
+        required == Required::Yes ? 1 : 0,
+        1,
+        [&value](StringView s) {
+            auto value_or_error = String::from_utf8(s);
+            if (value_or_error.is_error())
+                return false;
+
+            value = value_or_error.release_value();
+            return true;
+        }
+    };
+    add_positional_argument(move(arg));
+}
+
 template<Integral I>
 void ArgsParser::add_positional_argument(I& value, char const* help_string, char const* name, Required required)
 {

Userland/Libraries/LibCore/ArgsParser.h

@@ -88,6 +88,7 @@ public:
     void add_ignored(char const* long_name, char short_name, OptionHideMode hide_mode = OptionHideMode::None);
     void add_option(bool& value, char const* help_string, char const* long_name, char short_name, OptionHideMode hide_mode = OptionHideMode::None);
     void add_option(DeprecatedString& value, char const* help_string, char const* long_name, char short_name, char const* value_name, OptionHideMode hide_mode = OptionHideMode::None);
+    void add_option(String& value, char const* help_string, char const* long_name, char short_name, char const* value_name, OptionHideMode hide_mode = OptionHideMode::None);
     void add_option(StringView& value, char const* help_string, char const* long_name, char short_name, char const* value_name, OptionHideMode hide_mode = OptionHideMode::None);
     template<Integral I>
     void add_option(I& value, char const* help_string, char const* long_name, char short_name, char const* value_name, OptionHideMode hide_mode = OptionHideMode::None);
@@ -102,6 +103,7 @@ public:
     void add_positional_argument(Arg&&);
     void add_positional_argument(DeprecatedString& value, char const* help_string, char const* name, Required required = Required::Yes);
     void add_positional_argument(StringView& value, char const* help_string, char const* name, Required required = Required::Yes);
+    void add_positional_argument(String& value, char const* help_string, char const* name, Required required = Required::Yes);
     template<Integral I>
     void add_positional_argument(I& value, char const* help_string, char const* name, Required required = Required::Yes);
     void add_positional_argument(double& value, char const* help_string, char const* name, Required required = Required::Yes);