store_into: Accept float (by accepting generic floating point)

include/argparse/argparse.hpp

@@ -717,12 +717,13 @@ class Argument {
     return *this;
   }
 
-  auto &store_into(double &var) {
+  template <typename T, typename std::enable_if<std::is_floating_point<T>::value>::type * = nullptr>
+  auto &store_into(T &var) {
     if (m_default_value.has_value()) {
-      var = std::any_cast<double>(m_default_value);
+      var = std::any_cast<T>(m_default_value);
     }
     action([&var](const auto &s) {
-      var = details::parse_number<double, details::chars_format::general>()(s);
+      var = details::parse_number<T, details::chars_format::general>()(s);
       return var;
     });
     return *this;

test/test_store_into.cpp

@@ -124,6 +124,38 @@ TEST_CASE("Test store_into(double), default value, specified" *
   REQUIRE(res == 5.5);
 }
 
+// Float cases
+
+TEST_CASE("Test store_into(float), no default value, non specified" *
+          test_suite("store_into")) {
+  argparse::ArgumentParser program("test");
+  float res = -1.0f;
+  program.add_argument("--float-opt").store_into(res);
+
+  program.parse_args({"./test.exe"});
+  REQUIRE(res == -1.0f);
+}
+
+TEST_CASE("Test store_into(float), default value, non specified" *
+          test_suite("store_into")) {
+  argparse::ArgumentParser program("test");
+  float res = -1.0f;
+  program.add_argument("--float-opt").default_value(3.5f).store_into(res);
+
+  program.parse_args({"./test.exe"});
+  REQUIRE(res == 3.5f);
+}
+
+TEST_CASE("Test store_into(float), default value, specified" *
+          test_suite("store_into")) {
+  argparse::ArgumentParser program("test");
+  float res = -1.0f;
+  program.add_argument("--float-opt").default_value(3.5f).store_into(res);
+
+  program.parse_args({"./test.exe", "--float-opt", "5.5"});
+  REQUIRE(res == 5.5f);
+}
+
 TEST_CASE("Test store_into(string), no default value, non specified" *
           test_suite("store_into")) {
   argparse::ArgumentParser program("test");