Add integral_constant.

readme.md

@@ -1,3 +1,7 @@
 # 👷 Cute Engineering C++ Standard Library
 
 The ISO C++ Standard Library, ISO/IEC 14882
+
+## Overview
+
+The Cute Engineering C++ Standard Library is a minimalist implementation of the ISO C++ Standard Library. It provides only the essential features needed to fully utilize most core C++ language functionalities.

src/ce-stdcpp/type_traits

@@ -60,4 +60,16 @@ template <typename T> struct remove_cvref {
 
 template <typename T> using remove_cvref_t = typename remove_cvref<T>::type;
 
+// MARK: Integral Constant -----------------------------------------------------
+
+template <class T, T v> struct integral_constant {
+  static constexpr T value = v;
+  using value_type = T;
+  using type = integral_constant;
+
+  constexpr operator value_type() const noexcept { return value; }
+
+  constexpr value_type operator()() const noexcept { return value; }
+};
+
 } // namespace std