Experimental new, more flexible, way to construct sources and flagsvariadic_source_decl

1 files changed, 84 insertions, 27 deletions

diff --git a/src/ctor.h b/src/ctor.h
index 2ecef0e..8dd2ddd 100644
--- a/src/ctor.h
+++ b/src/ctor.h
@@ -11,6 +11,7 @@
 #include <cstddef>
 #include <functional>
 #include <string_view>
+#include <cassert>
 
 namespace ctor {
 
@@ -61,22 +62,42 @@ enum class toolchain
 	clang,
 };
 
-struct source
+struct output_file
 {
-	source(const char* file_) : file(file_) {} // convenience ctor
-
-	source(std::string_view file_) : source(file_, ctor::language::automatic) {}
-	source(std::string_view file_, ctor::language lang_) : file(file_), language(lang_) {}
-
-	source(std::string_view file_, std::string_view output_) : file(file_), output(output_) {}
-	source(std::string_view file_, ctor::language lang_, std::string_view output_) : file(file_), language(lang_), output(output_) {}
-
-	source(ctor::toolchain toolchain_, std::string_view file_) : file(file_), toolchain(toolchain_) {}
-	source(ctor::toolchain toolchain_, std::string_view file_, ctor::language lang_) : file(file_), toolchain(toolchain_), language(lang_) {}
-
-	source(ctor::toolchain toolchain_, std::string_view file_, std::string_view output_) : file(file_), toolchain(toolchain_), output(output_) {}
+	std::string file;
+};
 
-	source(ctor::toolchain toolchain_, std::string_view file_, ctor::language lang_, std::string_view output_) : file(file_), toolchain(toolchain_), language(lang_), output(output_) {}
+struct source
+{
+	template <class ... Args>
+		requires ((
+		          std::is_convertible_v<Args, std::string_view> ||
+		          std::is_same_v<Args, ctor::toolchain> ||
+		          std::is_same_v<Args, ctor::language> ||
+		          std::is_same_v<Args, ctor::output_file>
+		          ) && ...)
+	constexpr source(Args && ... arg)
+	{
+		([&]
+		{
+			if constexpr(std::is_convertible_v<Args, std::string_view>)
+			{
+				file = arg;
+			}
+			else if constexpr(std::is_same_v<Args, ctor::toolchain>)
+			{
+				toolchain = arg;
+			}
+			else if constexpr(std::is_same_v<Args, ctor::language>)
+			{
+				language = arg;
+			}
+			else if constexpr(std::is_same_v<Args, ctor::output_file>)
+			{
+				output = arg.file;
+			}
+		}(), ...);
+	}
 
 	std::string file;
 	ctor::toolchain toolchain{ctor::toolchain::any};
@@ -163,24 +184,60 @@ template<typename T>
 class flag
 {
 public:
-	flag(std::string_view str);
-	flag(const char* str) : flag(std::string_view(str)) {}
-	flag(T opt_) : opt(opt_) {}
-	flag(T opt_, std::string_view arg_, std::string_view arg2_ = "")
-		: opt(opt_), arg(arg_), arg2(arg2_) {}
-	flag(T opt_, const char* arg_, const char* arg2_ = "")
-		: opt(opt_), arg(arg_), arg2(arg2_) {}
-	flag(ctor::toolchain toolchain_, T opt_)
-		: toolchain(toolchain_), opt(opt_) {}
-	flag(ctor::toolchain toolchain_, T opt_, const char* arg_, const char* arg2_ = "")
-		: toolchain(toolchain_), opt(opt_), arg(arg_), arg2(arg2_) {}
-	flag(ctor::toolchain toolchain_, T opt_, std::string_view arg_, std::string_view arg2_ = "")
-		: toolchain(toolchain_), opt(opt_), arg(arg_), arg2(arg2_) {}
+	template <class ... Args>
+		requires ((
+		          std::is_convertible_v<Args, std::string_view> ||
+		          std::is_same_v<Args, ctor::toolchain> ||
+		          std::is_same_v<Args, T>
+		          ) && ...)
+	constexpr flag(Args && ... _arg)
+	{
+		constexpr std::size_t n = sizeof...(Args);
+		int state{}; // 0: opt, 1: arg1, 2: arg2, 3: error
+		([&]
+		{
+			if constexpr(std::is_convertible_v<Args, std::string_view>)
+			{
+				if constexpr(n == 1)
+				{
+					std::string str(_arg);
+					to_flag(str);
+				}
+				else
+				{
+					assert(state > 0); // opt must be before args
+					if(state == 1)
+					{
+						this->arg = _arg;
+					}
+					else
+					{
+						assert(state == 2); // up to 2 args supported
+						this->arg2 = _arg;
+					}
+					++state;
+				}
+			}
+			else if constexpr(std::is_same_v<Args, ctor::toolchain>)
+			{
+				toolchain = _arg;
+			}
+			else if constexpr(std::is_same_v<Args, T>)
+			{
+				assert(state == 0); // opt must be before args
+				opt = _arg;
+				++state;
+			}
+		}(), ...);
+	}
 
 	ctor::toolchain toolchain{ctor::toolchain::any};
 	T opt{};
 	std::string arg;
 	std::string arg2;
+
+private:
+	void to_flag(std::string_view str);
 };
 
 using c_flag = ctor::flag<ctor::c_opt>;