Bugfix - Argument::store into<bool> mishandling implicit value

include/argparse/argparse.hpp

@@ -694,12 +694,18 @@ class Argument {
   auto &store_into(bool &var) {
     if ((!m_default_value.has_value()) && (!m_implicit_value.has_value())) {
       flag();
+    } else {
+      if (!m_implicit_value.has_value()) {
+        m_implicit_value = !std::any_cast<bool>(m_default_value);
+      }
     }
     if (m_default_value.has_value()) {
       var = std::any_cast<bool>(m_default_value);
     }
-    action([&var](const auto & /*unused*/) {
-      var = true;
+
+    // If implicit value is defined after store_into, the wrong value might be set here.
+    // This is alright as long as it is described well in the manual.
+    action([&var, val = std::any_cast<bool>(m_implicit_value)](const auto & /*unused*/) {      var = val;
       return var;
     });
     return *this;

test/CMakeLists.txt

@@ -58,6 +58,7 @@ file(GLOB ARGPARSE_TEST_SOURCES
     test_parse_known_args.cpp
     test_equals_form.cpp
     test_prefix_chars.cpp
+    test_issue_413.cpp
 )
 set_source_files_properties(main.cpp
     PROPERTIES

test/test_issue_413.cpp

@@ -0,0 +1,36 @@
+#ifdef WITH_MODULE
+import argparse;
+#else
+#include <argparse/argparse.hpp>
+#endif
+#include <doctest.hpp>
+
+using doctest::test_suite;
+
+TEST_CASE("Regression test for issue 413" * test_suite("implicit_values")) {
+    argparse::ArgumentParser program;
+    bool nicearg = false;
+
+    program.add_argument("--deactivate")
+      .help("Disable BFS-based detector ordering and use geometric orientation")
+      .default_value(true)
+      .implicit_value(false)
+      .store_into(nicearg);
+
+    program.parse_args({"test"});
+    REQUIRE(nicearg == true);
+}
+
+TEST_CASE("Regression test for issue 413 [2]" * test_suite("implicit_values")) {
+    argparse::ArgumentParser program;
+    bool nicearg = true;
+
+    program.add_argument("--deactivate")
+      .help("Disable BFS-based detector ordering and use geometric orientation")
+      .default_value(true)
+      .implicit_value(false)
+      .store_into(nicearg);
+
+    program.parse_args({"test", "--deactivate"});
+    REQUIRE(nicearg == false);
+}