diff --git a/meta.hpp b/meta.hpp
index 96e6048948a190e95345c4df28ae2161581398a6..83022ff65da3cfb682d874c95d5028e9b975bafb 100644
--- a/meta.hpp
+++ b/meta.hpp
@@ -1,10 +1,42 @@
-#ifndef RLIB_MEelement_typeA_HPP_
-#define RLIB_MEelement_typeA_HPP_
+#ifndef RLIB_META_HPP_
+#define RLIB_META_HPP_
 
 #include <rlib/sys/os.hpp>
 #include <cstddef> // size_t
 #include <tuple>
 
+#include <type_traits>
+
+namespace rlib {
+    namespace impl {
+        template<typename T>
+        struct is_callable_helper {
+        private:
+            typedef char(&yes)[1];
+            typedef char(&no)[2];
+
+            struct Fallback { void operator()(); };
+            struct Derived : T, Fallback { };
+
+            template<typename U, U> struct Check;
+
+            template<typename>
+            static yes test(...);
+
+            template<typename C>
+            static no test(Check<void (Fallback::*)(), &C::operator()>*);
+
+            static constexpr bool value = sizeof(test<Derived>(0)) == sizeof(yes);
+        public:
+            static constexpr bool real_value = std::conditional<std::is_class<T>::value, impl::is_callable_helper<T>, std::is_function<T>>::type::value;
+        };
+    }
+    template<typename T>
+    struct is_callable : public std::integral_constant<bool, impl::is_callable_helper<T>::real_value> {
+    };
+} // end namespace rlib
+
+
 namespace rlib {
     #if RLIB_CXX_STD >= 2017
     namespace impl {
diff --git a/test/src/common.cc b/test/src/common.cc
index 946908f32f62da9a4fe1544e90f5cb7ea82a152a..709e228247ae6c6dca144d749a57113f5a105733 100644
--- a/test/src/common.cc
+++ b/test/src/common.cc
@@ -17,7 +17,7 @@ public:
 
 #if RLIB_CXX_STD >= 2017
 #include <rlib/functional.hpp>
-#include <rlib/traits.hpp>
+#include <rlib/meta.hpp>
 TEST_CASE("functional") {
     std::stringstream test_ss;
     auto test_func = [&](int i) {
diff --git a/test/src/header-include-all.cc b/test/src/header-include-all.cc
index 5c11f18b2feb0e204b40a15a62c9962a182de3bf..d76961070663ce81a87669198045bf55f219b77d 100644
--- a/test/src/header-include-all.cc
+++ b/test/src/header-include-all.cc
@@ -26,6 +26,6 @@
 #include <rlib/stdio.hpp>
 #include <rlib/stream.hpp>
 #include <rlib/terminal.hpp>
-#include <rlib/traits.hpp>
+#include <rlib/meta.hpp>
 
 int main() { return 0; }
diff --git a/traits.hpp b/traits.hpp
deleted file mode 100644
index 8b146706be7f42863bd398194eda6e395a48e7e2..0000000000000000000000000000000000000000
--- a/traits.hpp
+++ /dev/null
@@ -1,39 +0,0 @@
-#ifndef RLIB_TRAITS_HPP
-#define RLIB_TRAITS_HPP
-
-#include <rlib/require/cxx11>
-#include <type_traits>
-
-namespace rlib{
-    namespace impl {
-        template<typename T>
-        struct is_callable_helper {
-        private:
-            typedef char(&yes)[1];
-            typedef char(&no)[2];
-    
-            struct Fallback { void operator()(); };
-            struct Derived : T, Fallback { };
-    
-            template<typename U, U> struct Check;
-    
-            template<typename>
-            static yes test(...);
-    
-            template<typename C>
-            static no test(Check<void (Fallback::*)(), &C::operator()>*);
-    
-            static constexpr bool value = sizeof(test<Derived>(0)) == sizeof(yes);
-        public:
-            static constexpr bool real_value = std::conditional<std::is_class<T>::value, impl::is_callable_helper<T>, std::is_function<T>>::type::value;
-        };
-    } //impl
-} //rlib
-
-namespace rlib {
-    template<typename T>
-    struct is_callable : public std::integral_constant<bool, impl::is_callable_helper<T>::real_value> {
-    };
-}
-
-#endif