Add Argument::store_into(std::set<int||string> &var) method

include/argparse/argparse.hpp

@@ -36,6 +36,7 @@ SOFTWARE.
 #include <algorithm>
 #include <any>
 #include <array>
+#include <set>
 #include <charconv>
 #include <cstdlib>
 #include <functional>
@@ -755,6 +756,34 @@ public:
     return *this;
   }
 
+  auto &store_into(std::set<std::string> &var) {
+    if (m_default_value.has_value()) {
+      var = std::any_cast<std::set<std::string>>(m_default_value);
+    }
+    action([this, &var](const std::string &s) {
+      if (!m_is_used) {
+        var.clear();
+      }
+      m_is_used = true;
+      var.insert(s);
+    });
+    return *this;
+  }
+
+  auto &store_into(std::set<int> &var) {
+    if (m_default_value.has_value()) {
+      var = std::any_cast<std::set<int>>(m_default_value);
+    }
+    action([this, &var](const std::string &s) {
+      if (!m_is_used) {
+        var.clear();
+      }
+      m_is_used = true;
+      var.insert(details::parse_number<int, details::radix_10>()(s));
+    });
+    return *this;
+  }
+
   auto &append() {
     m_is_repeatable = true;
     return *this;

test/test_store_into.cpp

@@ -239,3 +239,50 @@ TEST_CASE("Test store_into(vector of int), default value, multi valued, specifie
   program.parse_args({"./test.exe", "--intvector-opt", "3", "4"});
   REQUIRE(res == std::vector<int>{3, 4});
 }
+
+TEST_CASE("Test store_into(set of int), default value, multi valued, specified" *
+          test_suite("store_into")) {
+
+  {
+    argparse::ArgumentParser program("test");
+    std::set<int> res;
+    program.add_argument("--intset-opt").nargs(2).default_value(
+                                                        std::set<int>{1, 2}).store_into(res);
+
+    program.parse_args({"./test.exe", "--intset-opt", "3", "4"});
+    REQUIRE(res == std::set<int>{3, 4});
+  }
+
+  {
+    argparse::ArgumentParser program("test");
+    std::set<int> res;
+    program.add_argument("--intset-opt").nargs(2).default_value(
+                                                     std::set<int>{1, 2}).store_into(res);
+    program.parse_args({"./test.exe"});
+    REQUIRE(res == std::set<int>{1, 2});
+  }
+}
+
+TEST_CASE("Test store_into(set of string), default value, multi valued, specified" *
+          test_suite("store_into")) {
+
+  {
+    argparse::ArgumentParser program("test");
+    std::set<std::string> res;
+    program.add_argument("--stringset-opt").nargs(2).default_value(
+                                                        std::set<std::string>{"1", "2"}).store_into(res);
+
+    program.parse_args({"./test.exe", "--stringset-opt", "3", "4"});
+    REQUIRE(res == std::set<std::string>{"3", "4"});
+  }
+
+  {
+    argparse::ArgumentParser program("test");
+    std::set<std::string> res;
+    program.add_argument("--stringset-opt").nargs(2).default_value(
+                                                        std::set<std::string>{"1", "2"}).store_into(res);
+    program.parse_args({"./test.exe"});
+    REQUIRE(res == std::set<std::string>{"1", "2"});
+  }
+}
+