Adds support for the compile time formatter

1 files changed, 111 insertions, 0 deletions

diff --git a/libadhocutil/compileTimeFormatter.h b/libadhocutil/compileTimeFormatter.h
new file mode 100644
index 0000000..aa30e20
--- /dev/null
+++ b/libadhocutil/compileTimeFormatter.h
@@ -0,0 +1,111 @@
+#include <iostream>
+#include <string.h>
+#include <boost/static_assert.hpp>
+
+namespace AdHoc {
+	template <char...> struct Buffer { };
+
+	template <char stop, char ...>
+	struct Upto {
+		template<typename stream>
+		static auto stuff(stream &, const Buffer<> & f)
+		{
+			return f;
+		}
+	};
+	template <char stop, char s0, char... sn>
+	struct Upto<stop, s0, sn...> {
+		template<typename stream, char... sm>
+		static auto stuff(stream & s, const Buffer<sm...> &)
+		{
+			return Upto<stop, sn...>::stuff(s, Buffer<sm..., s0>());
+		}
+	};
+	template <char stop, char... sn>
+	struct Upto<stop, stop, sn...> {
+		template<typename stream, char... sm>
+		static auto stuff(stream & s, const Buffer<sm...> &)
+		{
+			char buf[] = {sm...};
+			s.write(buf, sizeof...(sm));
+			return Buffer<stop, sn...>();
+		}
+	};
+	template <char stop, char... sn>
+	struct Upto<stop, 0, sn...> {
+		template<typename stream, char... sm>
+		static auto stuff(stream & s, const Buffer<sm...> &)
+		{
+			char buf[] = {sm...};
+			s.write(buf, sizeof...(sm));
+			return Buffer<0, sn...>();
+		}
+	};
+
+	template <typename stream, char ... sn>
+	struct StreamWriter {
+		template<typename ... Pn>
+  	static void write(stream & s, const Pn & ... pn)
+    {
+    	next(s, Upto<'%', sn...>::stuff(s, Buffer<>()), pn...);
+    }
+		template<typename ... Pn, char... ssn, template <char...> class Buffer>
+		static void next(stream & s, const Buffer<ssn...>&, const Pn & ... pn)
+		{
+			StreamWriter<stream, ssn...>::write(s, pn...);
+		}
+	};
+
+	template<typename stream>
+	struct StreamWriter<stream> {
+		template<typename ... Pn>
+		static void write(stream &, const Pn & ...) { }
+	};
+
+	template<typename stream>
+	struct StreamWriter<stream, 0> {
+		template<typename ... Pn>
+		static void write(stream &, const Pn & ...) { }
+	};
+
+	// Default stream writer formatter
+	template<typename stream, char ... sn>
+	struct StreamWriter<stream, '%', '?', sn...> {
+		template<typename P, typename ... Pn>
+		static void write(stream & s, const P & p, const Pn & ... pn)
+		{
+			s << p;
+			StreamWriter<stream, sn...>::write(s, pn...);
+		}
+	};
+
+	// Unknown stream writer formatter
+	template<typename stream, char ... sn>
+	struct StreamWriter<stream, '%', sn...> {
+		template<typename ... Pn>
+		static void write(stream &, const Pn & ...)
+		{
+			BOOST_STATIC_ASSERT_MSG(!&err, "invalid format string/arguments");
+		}
+		static int err;
+	};
+
+	template <const char * const & S, char s0 = *S, int offset = 0, char ... sn>
+	struct Formatter {
+		template<typename stream, typename ... Pn>
+		static void write(stream & s, const Pn & ... pn)
+		{
+			Formatter<S, S[offset], offset + 1, sn..., S[offset]>::write(s, pn...);
+		}
+	};
+
+	template <const char * const & S, int offset, char ... sn>
+	struct Formatter<S, 0, offset, sn...> {
+		template<typename stream, typename ... Pn>
+		static void write(stream & s, const Pn & ... pn)
+		{
+			StreamWriter<stream, sn...>::write(s, pn...);
+		}
+	};
+}
+