lib: restructure stdx headers and rename to opt, relocate example

Move stdx.hpp into a stdx/ subdirectory and rename to opt.hpp, reflecting
its specific purpose. Rename stdx.cc to opt.cc accordingly.

Update includes in both the library and examples to reflect the new path.

Also move must_pass.cc and its CMake config into examples/must_pass/ for
better organization and consistency.

No functional changes made.

Signed-off-by: Amlal El Mahrouss <amlal@nekernel.org>

1 files changed, 110 insertions, 0 deletions

diff --git a/lib/stdx/opt.hpp b/lib/stdx/opt.hpp
new file mode 100644
index 0000000..66ef4a5
--- /dev/null
+++ b/lib/stdx/opt.hpp
@@ -0,0 +1,110 @@
+/* 
+ * File: stdx.hpp
+ * Author: Amlal El Mahrouss, 
+ * Copyright 2023-2025, Amlal El Mahrouss all rights reserved. 
+ */
+
+#ifndef _STDX_HPP
+#define _STDX_HPP
+
+#include <stdexcept>
+#include <utility>
+
+namespace stdx
+{
+	enum class ret
+	{
+		okay,
+		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... Lst>
+	inline stdx::ret eval(Teller tell, Lst&&... arg)
+	{
+		return tell(std::forward<Lst>(arg)...) ? stdx::ret::okay : 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);
+			}
+		};
+	} // namespace traits
+
+	template <typename... Lst>
+	inline ret eval_less_than(Lst&&... arg)
+	{
+		static traits::int_less_than_teller eq;
+		return eq(std::forward<Lst>(arg)...) ? ret::okay : ret::err;
+	}
+
+	template <typename... Lst>
+	inline ret eval_eq(Lst&&... arg)
+	{
+		static traits::int_eq_teller less_than;
+		return less_than(std::forward<Lst>(arg)...) ? ret::okay : ret::err;
+	}
+
+	template <typename... Lst>
+	inline ret eval_greater(Lst&&... arg)
+	{
+		static traits::int_greater_than_teller greater_than;
+		return greater_than(std::forward<Lst>(arg)...) ? ret::okay : ret::err;
+	}
+
+} /* namespace stdx */
+
+#endif /* ifndef _STDX_HPP */