Update README.md

README.md

@@ -2,11 +2,65 @@
 ![logo.png](logo.png)
 
 ## Description
-Use the latest STL implementation in C++14
-
-(Code migration in progress)
+**Use the latest STL implementation in C++14**
+
+```c++
+// All implementation is written under C++14 standard
+#include "preview/ranges.h"
+
+auto map = preview::views::iota('A', 'E') | 
+           preview::views::enumerate | 
+           preview::ranges::to<std::map>();
+
+std::cout << map[0] << ' '
+          << map[1] << ' '
+          << map[2] << '\n';
+// A B C
+```
+
+**`preview` is standard-conforming, and is compatible with existing STL**
+```c++
+auto r = preview::views::iota(0) |
+      preview::views::take(10) |
+      preview::views::filter([](auto x) { return x % 2 == 0; });
+
+// Compatible with both pre C++20 and post C++20 std::iterator_traits
+static_assert(std::is_same<
+    std::iterator_traits<decltype(r.begin())>::reference,
+    int
+>::value, "");
+
+// Others such as std::get, std::tuple_size are also compatible 
+```
+
+**Up to C++26 STL are available**
+```c++
+void foo(preview::span<int>) {}
+
+int main() {
+  // span with C++26 standard
+  foo({1, 2, 3});
+  
+  preview::variant<int, float, double> v{1.0f};
+  v.visit([](auto x) {
+    // member visit(): C++26 standard
+  });
+  
+  // views::concat
+  std::vector<char> v = {'h', 'e', 'l'};
+  std::string s = "lo, ";
+  preview::string_view sv = "world";
+  std::list<char> l = {'!'};
+
+  for (auto c : preview::views::concat(v, s, sv, l)) {
+    std::cout << c;
+  }
+  // hello, world!
+}
+```
 
 ## Compiler Support
+[![Build Status](https://github.com/lackhole/stl-preview/actions/workflows/cmake-multi-platform.yml/badge.svg)](https://github.com/lackhole/stl-preview/actions/workflows/cmake-multi-platform.yml)
 
 | Compiler    | Minimum version tested                | Maximum version tested                |
 |-------------|---------------------------------------|---------------------------------------|
@@ -22,7 +76,10 @@ Use the latest STL implementation in C++14
 Description 
 * ![](https://img.shields.io/badge/C++XX-C++YY-CCEEFF): C++YY standard implemented in C++XX
 * ![](https://img.shields.io/badge/C++YY-red): C++YY standard, not implemented yet
-
+* If the implementation is impossible(i.e., needs compiler support / hardware info) it is marked as **N/A**
+* Some features are working in progress
+* **Introduced**: First introduced version 
+* **Revision**: Behavior changed/updated version
 
 -----