diff --git a/CMakeLists.txt b/CMakeLists.txt
index b43e0e1..b188859 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -67,6 +67,11 @@ SOURCES
     examples/sugar.cpp
 )
 
+cppm_target_define(reflection BINARY
+SOURCES
+    examples/reflection.cpp
+)
+
 cppm_target_define(print BINARY
 SOURCES
     examples/print.cpp
@@ -135,6 +140,10 @@ cppm_target_dependencies(sugar
    ${serdepp_global_deps}
    serdepp)
 
+cppm_target_dependencies(reflection
+   ${serdepp_global_deps}
+   serdepp)
+
 cppm_target_dependencies(print
    ${serdepp_global_deps}
    serdepp)
@@ -165,6 +174,7 @@ cppm_target_install(variant_example)
 cppm_target_install(parse_file_example)
 cppm_target_install(struct_attribute_example)
 cppm_target_install(sugar)
+cppm_target_install(reflection)
 cppm_target_install(print)
 cppm_target_install(pointer)
 
diff --git a/README.md b/README.md
index 95c4e91..0da1995 100644
--- a/README.md
+++ b/README.md
@@ -34,6 +34,7 @@ c++17 low cost serialize deserialize adaptor library like rust serde.rs
 - [x] [attributes](#Attributes) and custom attribute support (value_or_struct, default, multi_key ...)
 - [x] variant support (std::variant<int, std::vector<...>, UserType, EnumType...>) [example](examples/variant.cpp)
 - [x] pointer support (T*, std::shared_ptr<T>, std::unique_ptr<T>)
+- [x] reflection support (BETA) (mem_get(member_name) or mem_get<index>())
 
 ## Serdepp Strcuture
 ![Serdepp structure](Serdepp_Structure.png)
@@ -65,12 +66,12 @@ int main() {
     ex.number_ = 1024;
     ex.vec_ = {"a", "b", "c"};
     ex.tenum_ = t_enum::B;
+    //std::cout << ex << "\n";
 
     nlohmann::json json_from_ex = serde::serialize<nlohmann::json>(ex);
     example ex_from_json = serde::deserialize<example>(json_from_ex);
 
-    fmt::print("json:{}\n",json_from_ex.dump(4));
-
+    std::cout << "json: " << json_from_ex.dump(4) << "\n";
     fmt::print("fmt:{}\n",ex_from_json);
 }
 
diff --git a/cppm.toml b/cppm.toml
index 25b771c..0488f86 100644
--- a/cppm.toml
+++ b/cppm.toml
@@ -45,6 +45,10 @@
     name = "sugar"
     source = ["examples/sugar.cpp"]
 
+[[example]]
+    name = "reflection"
+    source = ["examples/reflection.cpp"]
+
 [[example]]
     name = "print"
     source = ["examples/print.cpp"]
@@ -53,6 +57,10 @@
     name = "pointer"
     source = ["examples/pointer.cpp"]
 
+#[[example]]
+#    name = "tuple_sort"
+#    source = ["examples/tuple_sort.cpp"]
+
 #[[example]]
 #    name = "sol2_example"
 #    source = ["examples/sol2.cpp"]
diff --git a/examples/example.cpp b/examples/example.cpp
index f46ae40..d7125ce 100644
--- a/examples/example.cpp
+++ b/examples/example.cpp
@@ -6,8 +6,6 @@
 #include "serdepp/adaptor/rapidjson.hpp"
 #include <memory>
 
-using namespace serde::ostream;
-
 enum class tenum {INPUT, OUTPUT, INPUT_2 , OUTPUT_2 };
 
 
@@ -16,6 +14,7 @@ struct nested {
                  (&Self::version, "version", value_or_struct)
                  (&Self::opt_desc ,"opt_desc")
                  [attributes(default_{"default value"})]
+
                  (&Self::desc ,"desc")
                  .no_remain())
     std::string version;
diff --git a/examples/print.cpp b/examples/print.cpp
index 0093299..1bbb118 100644
--- a/examples/print.cpp
+++ b/examples/print.cpp
@@ -34,7 +34,7 @@ int main(int argc, char *argv[])
 
     auto j_flatten = serde::deserialize<std::vector<Test>>(jflat);
 
-    std::cout << serde::serialize<serde::serde_sstream>(j_flatten).str();
+    std::cout << serde::to_string(j_flatten) << "\n";
     
     return 0;
 }
diff --git a/examples/reflection.cpp b/examples/reflection.cpp
new file mode 100644
index 0000000..c9a8ec2
--- /dev/null
+++ b/examples/reflection.cpp
@@ -0,0 +1,22 @@
+#include <serdepp/serde.hpp>
+#include <serdepp/adaptor/reflection.hpp>
+
+struct Test {
+    DERIVE_SERDE(Test,
+            (&Self::test, "test")
+            (&Self::str, "str"))
+    int test;
+    std::string str;
+};
+
+int main(int argc, char *argv[])
+{
+    auto t = Test{1,"hello"};
+    std:: cout << t << "\n";
+    serde::mem_get<std::string>(t, "str") = "why";
+    serde::mem_get<int, 0>(t) = 200;
+    std:: cout << t << "\n";
+
+    return 0;
+}
+
diff --git a/examples/sugar.cpp b/examples/sugar.cpp
index 2c26a41..22bc609 100644
--- a/examples/sugar.cpp
+++ b/examples/sugar.cpp
@@ -19,13 +19,13 @@ namespace serde::attribute {
             }
         };
     }
-    constexpr static auto tttt = detail::tttt{};
+    [[maybe_unused]] constexpr static auto tttt = detail::tttt{};
 }
 
 
 struct Test {
     DERIVE_SERDE(Test,
-            [attributes(flatten, default_(""))]
+            [attributes(flatten)]
             (&Self::test, "test")
             [attributes(flatten, default_(""))]
             (&Self::str, "str"))
@@ -35,7 +35,7 @@ struct Test {
 
 int main(int argc, char *argv[])
 {
-    fmt::print("{}\n",Test{1});
+    std::cout << Test{1} << "\n";
     
     return 0;
 }
diff --git a/examples/variant.cpp b/examples/variant.cpp
index d0ad88f..527d325 100644
--- a/examples/variant.cpp
+++ b/examples/variant.cpp
@@ -41,6 +41,7 @@ int main() {
 
     fmt::print("------\n");
     auto j_flatten = deserialize<std::vector<Test>>(jflat);
+    fmt::print("------\n");
     auto j_none    = deserialize<std::vector<Test>>(j);
     fmt::print("{}\n",serialize<nlohmann::json>(j_flatten).dump(4));
     fmt::print("{}\n",serialize<nlohmann::json>(j_none).dump(4));
diff --git a/include/serdepp/adaptor/reflection.hpp b/include/serdepp/adaptor/reflection.hpp
new file mode 100644
index 0000000..cbe4a02
--- /dev/null
+++ b/include/serdepp/adaptor/reflection.hpp
@@ -0,0 +1,116 @@
+#pragma once
+
+#ifndef __SERDEPP_ADAPTOR_RFLECTION_HPP__
+#define __SERDEPP_ADAPTOR_RFLECTION_HPP__
+
+#include <serdepp/serde.hpp>
+#include <string_view>
+
+namespace serde {
+    template<class T>
+    struct reflect_from_name {
+        //DERIVE_SERDE(reflect<T>,(&Self::key, "key")(&Self::member, "member"))
+        reflect_from_name() = default;
+        reflect_from_name(std::string_view member) : key(member) {}
+        std::string_view key;
+        T* member = nullptr;
+    };
+
+    template<class T, size_t idx>
+    struct reflect_from_index {
+        constexpr static size_t find_idx = idx;
+        //DERIVE_SERDE(reflect<T>,(&Self::key, "key")(&Self::member, "member"))
+        reflect_from_index() = default;
+        size_t index = 0;
+        T* member = nullptr;
+    };
+
+    template<class T>
+    struct serde_adaptor_helper<reflect_from_name<T>> : derive_serde_adaptor_helper<reflect_from_name<T>> {
+        inline constexpr static bool is_null(reflect_from_name<T> &adaptor, std::string_view key) { return false; }
+        inline constexpr static size_t size(reflect_from_name<T> &adaptor) { return 1; }
+        inline constexpr static bool is_struct(reflect_from_name<T> &adaptor) { return true; }
+    };
+
+    template<class T, size_t idx>
+    struct serde_adaptor_helper<reflect_from_index<T,idx>> : derive_serde_adaptor_helper<reflect_from_index<T, idx>> {
+        inline constexpr static bool is_null(reflect_from_index<T, idx> &adaptor, std::string_view key) { return false; }
+        inline constexpr static size_t size(reflect_from_index<T, idx> &adaptor) { return 1; }
+        inline constexpr static bool is_struct(reflect_from_index<T, idx> &adaptor) { return true; }
+    };
+
+    template<typename U, typename T>
+    struct serde_adaptor<reflect_from_name<U>, T, std::enable_if_t<std::is_same_v<U, remove_cvref_t<T>>>> {
+        constexpr static void from(reflect_from_name<U>& s, std::string_view key, T& data){
+            if(key == s.key) {
+                s.member = &data;
+            }
+        }
+        static void into(reflect_from_name<U>& s, std::string_view key, const T& data) {
+            throw serde::unimplemented_error("serde_adaptor<reflect_from_name>::into(reflect_from_name, key, data)");
+        }
+    };
+
+    template<typename U, typename T>
+    struct serde_adaptor<reflect_from_name<U>, T , std::enable_if_t<!std::is_same_v<U, remove_cvref_t<T>>>> {
+        static void from(reflect_from_name<U>& s, std::string_view key, T& data){
+            if(key == s.key) {
+                std::string error = std::string(nameof::nameof_type<U>());
+                throw serde::type_error(error + " != " + std::string(nameof::nameof_type<remove_cvref_t<T>>()));
+            }
+        }
+        static void into(reflect_from_name<U>& s, std::string_view key, const T& data) {
+            throw serde::unimplemented_error("serde_adaptor<reflect_from_name>::into(reflect_from_name, key, data)");
+        }
+    };
+
+    template<typename U, typename T, size_t index>
+    struct serde_adaptor<reflect_from_index<U, index>, T, std::enable_if_t<std::is_same_v<U, remove_cvref_t<T>>>> {
+        constexpr static void from(reflect_from_index<U, index>& s, std::string_view key, T& data){
+            if(s.index == s.find_idx) {
+                s.member = &data;
+            }
+            s.index++;
+        }
+        static void into(reflect_from_index<U,index>& s, std::string_view key, const T& data) {
+            throw serde::unimplemented_error("serde_adaptor<reflect_from_name>::into(reflect_from_name, key, data)");
+        }
+    };
+    
+    template<typename U, typename T, size_t index>
+    struct serde_adaptor<reflect_from_index<U, index>, T, std::enable_if_t<!std::is_same_v<U, remove_cvref_t<T>>>> {
+        static void from(reflect_from_index<U, index>& s, std::string_view key, T& data){
+            if(s.index == s.find_idx) {
+                std::string error = std::string(nameof::nameof_type<U>());
+                throw serde::type_error(error + " != " + std::string(nameof::nameof_type<remove_cvref_t<T>>()));
+            }
+            s.index++;
+        }
+        static void into(reflect_from_index<U,index>& s, std::string_view key, const T& data) {
+            throw serde::unimplemented_error("serde_adaptor<reflect_from_name>::into(reflect_from_name, key, data)");
+        }
+    };
+    
+
+    template<typename M, class T>
+    constexpr M& mem_get(T& type, std::string_view member_name) {
+        auto ref = serde::reflect_from_name<M>(member_name);
+        serde::deserialize_to(ref, type);
+        if(ref.member == nullptr) {
+            throw serde::type_error("can't find member: " + std::string(member_name));
+        }
+        return *ref.member;
+    }
+
+    template<typename M, size_t idx, class T>
+    constexpr M& mem_get(T& type) {
+        auto ref = serde::reflect_from_index<M,idx>();
+        serde::deserialize_to(ref, type);
+        if(ref.member == nullptr) {
+            throw serde::type_error("out of index: " + std::to_string(idx));
+        }
+        return *ref.member;
+    }
+}
+
+#endif
diff --git a/include/serdepp/exception.hpp b/include/serdepp/exception.hpp
index dfec819..90f7e9c 100644
--- a/include/serdepp/exception.hpp
+++ b/include/serdepp/exception.hpp
@@ -37,6 +37,15 @@ namespace serde {
         std::string what_;
     };
 
+    struct type_error : exception {
+    public:
+        explicit type_error(std::string what) : what_("type error: " + what + '\n') {}
+        virtual ~type_error() noexcept override = default;
+        virtual const char* what() const noexcept override {return what_.c_str();}
+    protected:
+        std::string what_;
+    };
+
     struct unregisted_data_error : exception {
     public:
         explicit unregisted_data_error(std::string what) : what_("unregisted data: " + what + '\n') {}
diff --git a/include/serdepp/serde.hpp b/include/serdepp/serde.hpp
index f54004a..3b21c89 100644
--- a/include/serdepp/serde.hpp
+++ b/include/serdepp/serde.hpp
@@ -6,5 +6,6 @@
 #include <serdepp/utility.hpp>
 #include <serdepp/adaptor/sstream.hpp>
 #include <serdepp/ostream.hpp>
+using namespace serde::ostream;
 
 #endif
diff --git a/include/serdepp/serializer.hpp b/include/serdepp/serializer.hpp
index 4745a4b..6f5ac5a 100644
--- a/include/serdepp/serializer.hpp
+++ b/include/serdepp/serializer.hpp
@@ -513,14 +513,14 @@ namespace serde
 
     template<typename Format, typename=void>
     struct serde_type_checker {
-        static bool is_integer(Format& format);
-        static bool is_sequence(Format& format);
-        static bool is_map(Format& format);
-        static bool is_float(Format& format);
-        static bool is_string(Format& format);
-        static bool is_bool(Format& format);
-        static bool is_null(Format& format);
-        static bool is_struct(Format& format);
+        static bool is_integer(Format& format)  { return true; }
+        static bool is_sequence(Format& format) { return true; }
+        static bool is_map(Format& format)      { return true; }
+        static bool is_float(Format& format)    { return true; }
+        static bool is_string(Format& format)   { return true; }
+        static bool is_bool(Format& format)     { return true; }
+        static bool is_null(Format& format)     { return true; }
+        static bool is_struct(Format& format)   { return true; }
     };
 
     template<class T>
@@ -574,6 +574,7 @@ namespace serde
             data = deserialize<T>(format);
             return false;
         } catch(std::exception& ex) {
+            std::cout << "error \n";
             return true;
         }
     }
@@ -581,8 +582,8 @@ namespace serde
     template<class Format, class V, class Cur, class ...T>
     constexpr void serde_variant_iter(Format& format, V& data) {
         if constexpr (sizeof...(T) != 0) {
-            bool is_find = serde_variant_setter<Format, Cur, V>(format, data);
-            if(!is_find) return;
+            bool is_not_find = serde_variant_setter<Format, Cur, V>(format, data);
+            if(!is_not_find) return;
             serde_variant_iter<Format, V, T...>(format, data);
         } else {
             if(serde_variant_setter<Format,
diff --git a/include/serdepp/utility.hpp b/include/serdepp/utility.hpp
index cb83010..0c4e0bd 100644
--- a/include/serdepp/utility.hpp
+++ b/include/serdepp/utility.hpp
@@ -24,4 +24,6 @@
             __VA_ARGS__;                     \
     }                                        \
 
+#define _SF_(name) (&Self::name, #name)
+
 #endif