Remove positional argument support for dest option

include/argparse.hpp

@@ -1213,9 +1213,7 @@ namespace argparse
 
                     auto get_dest_name() const -> std::string override
                     {
-                        return m_impl.get_dest().empty()
-                            ? get_name()
-                            : m_impl.get_dest();
+                        return get_name();
                     }
 
                     auto get_metavar_name() const -> std::string override
@@ -1960,6 +1958,10 @@ namespace argparse
 
                     auto dest(std::string dest) -> ArgumentBuilder &
                     {
+                        if (is_positional())
+                        {
+                            throw option_error("'dest' is an invalid argument for positionals");
+                        }
                         m_options.dest = std::move(dest);
                         return *this;
                     }

test/unittest/test_argument_parser.cpp

@@ -313,6 +313,20 @@ TEST_CASE("ArgumentParser replaces '{prog}' with program name in usage text")
     CHECK(parser.format_help() == "usage: program [options]"s);
 }
 
+TEST_CASE("Adding a positional argument with dest option set results in error")
+{
+    auto parser = argparse::ArgumentParser();
+
+    CHECK_THROWS_WITH_AS(parser.add_argument("pos").dest("foo"), "'dest' is an invalid argument for positionals", argparse::option_error);
+}
+
+TEST_CASE("Adding an optional argument with dest option does not result in error")
+{
+    auto parser = argparse::ArgumentParser();
+
+    CHECK_NOTHROW(parser.add_argument("-o").dest("foo"));
+}
+
 TEST_CASE("Adding a positional argument with required option set results in error")
 {
     auto parser = argparse::ArgumentParser();

test/unittest/test_parsing_positional.cpp

@@ -129,16 +129,6 @@ TEST_CASE("The resulting attribute name for positional argument is based on its
     CHECK(args.get("foo"));
 }
 
-TEST_CASE("The resulting attribute name for positional argument is based on dest parameter")
-{
-    auto parser = argparse::ArgumentParser();
-    parser.add_argument("foo").dest("bar");
-
-    auto const args = parser.parse_args(2, cstr_arr{"prog", "val"});
-
-    CHECK(args.get("bar"));
-}
-
 TEST_CASE_TEMPLATE("Parsing a positional argument with choices set accepts one of the values", T, char, signed char, unsigned char, short int, unsigned short int, int, unsigned int, long int, unsigned long int, long long int, unsigned long long int, float, double, long double, std::string, foo::Custom)
 {
     auto parser = argparse::ArgumentParser().handle(argparse::Handle::none);