meta: add stdx (C++ std extension)

1 files changed, 102 insertions, 0 deletions

diff --git a/stdx b/stdx
new file mode 100644
index 0000000..ec79f72
--- /dev/null
+++ b/stdx
@@ -0,0 +1,102 @@
+/* 
+ * Written by Amlal El Mahrouss, 
+ * Copyright 2023, all rights reserved. 
+ */
+
+#ifndef _STDX
+#define _STDX
+
+#include <stdexcept>
+
+namespace stdx
+{
+  enum class ret
+  {
+    Ok,
+    Err
+  };
+
+  struct opt final
+  {
+    explicit opt(const ret& ret)
+      : m_ret(ret)
+    {}
+
+    opt& expect(const char* input)
+    {
+       if (m_ret == ret::Err)
+       {
+          throw std::runtime_error(input);
+       }
+  
+        return *this;
+    }
+
+  private:
+    ret m_ret;
+
+  };
+
+  template <typename Teller, typename... Args>
+  stdx::ret eval(Teller tell, Args... arg)
+  {
+    return tell(arg...) ? stdx::ret::Ok : stdx::ret::Err;
+  }
+
+  namespace traits
+  {
+    struct int_eq_teller
+    {
+      explicit int_eq_teller() {}
+    
+      bool operator()(int a, int b)
+      {
+        return (a == b);
+      }
+    };
+
+    struct int_greater_than_teller
+    {
+      explicit int_greater_than_teller() {}
+    
+      bool operator()(int a, int b)
+      {
+        return (a > b);
+      }
+    };
+
+    struct int_less_than_teller
+    {
+      explicit int_less_than_teller() {}
+    
+      bool operator()(int a, int b)
+      {
+        return (a < b);
+      }
+    };
+  }
+
+  template <typename... Lst>
+  ret eval_less_than(Lst... arg)
+  {
+    static traits::int_less_than_teller eq;
+    return eq(arg...) ? ret::Ok : ret::Err;
+  }
+
+  template <typename... Lst>
+  ret eval_eq(Lst... arg)
+  {
+    static traits::int_eq_teller less_than;
+    return less_than(arg...) ? ret::Ok : ret::Err;
+  }
+
+  template <typename... Lst>
+  ret eval_greater(Lst... arg)
+  {
+    static traits::int_greater_than_teller greater_than;
+    return greater_than(arg...) ? ret::Ok : ret::Err;
+  }
+
+} /* namespace stdx */
+
+#endif /* ifndef _STDX */