Simplify similar specializations of AutoConversion and FormatConvert using base structs

1 files changed, 22 insertions, 76 deletions

diff --git a/cxxformat.hpp b/cxxformat.hpp
index d4e8dfd..b02fe4f 100644
--- a/cxxformat.hpp
+++ b/cxxformat.hpp
@@ -27,68 +27,35 @@ using FormatException = std::invalid_argument;
 template<typename To, typename From, typename Enable = void>
 struct FormatConvert {};
 
-template<typename From>
-struct FormatConvert<std::intmax_t, From, std::enable_if_t<std::is_signed_v<From> && std::is_integral_v<From>>>
+template<typename To, typename From>
+struct ImplicitConversion
 {
-	static constexpr std::intmax_t convert(From from)
+	static constexpr To convert(From from)
 	{
 		return from;
 	}
 };
 
 template<typename From>
-struct FormatConvert<std::intmax_t, From, std::enable_if_t<std::is_unsigned_v<From> && std::is_integral_v<From> && (sizeof(From) < sizeof(std::intmax_t))>>
-{
-	static constexpr std::intmax_t convert(From from)
-	{
-		return from;
-	}
-};
+struct FormatConvert<std::intmax_t, From, std::enable_if_t<std::is_signed_v<From> && std::is_integral_v<From>>> : ImplicitConversion<std::intmax_t, From> {};
 
 template<typename From>
-struct FormatConvert<std::uintmax_t, From, std::enable_if_t<std::is_unsigned_v<From> && std::is_integral_v<From>>>
-{
-	static constexpr std::uintmax_t convert(From from)
-	{
-		return from;
-	}
-};
+struct FormatConvert<std::intmax_t, From, std::enable_if_t<std::is_unsigned_v<From> && std::is_integral_v<From> && (sizeof(From) < sizeof(std::intmax_t))>> : ImplicitConversion<std::intmax_t, From> {};
+
+template<typename From>
+struct FormatConvert<std::uintmax_t, From, std::enable_if_t<std::is_unsigned_v<From> && std::is_integral_v<From>>> : ImplicitConversion<std::uintmax_t, From> {};
 
 template<typename String>
-struct FormatConvert<std::string_view, String, std::enable_if_t<std::is_convertible_v<String, std::string_view>>>
-{
-	static constexpr std::string_view convert(const String &str)
-	{
-		return str;
-	}
-};
+struct FormatConvert<std::string_view, String, std::enable_if_t<std::is_convertible_v<String, std::string_view>>> : ImplicitConversion<std::string_view, const String &> {};
 
 template<typename From>
-struct FormatConvert<double, From, std::enable_if_t<std::is_convertible_v<From, double> && !std::is_integral_v<From>>>
-{
-	static constexpr double convert(const From& val)
-	{
-		return val;
-	}
-};
+struct FormatConvert<double, From, std::enable_if_t<std::is_convertible_v<From, double> && !std::is_integral_v<From>>> : ImplicitConversion<double, const From &> {};
 
 template<typename Pointer>
-struct FormatConvert<const void *, Pointer, std::enable_if_t<std::is_pointer_v<Pointer> && !std::is_array_v<std::remove_pointer_t<Pointer>> && !std::is_same_v<std::remove_pointer_t<Pointer>, char>>>
-{
-	static constexpr const void *convert(const Pointer* pointer)
-	{
-		return pointer;
-	}
-};
+struct FormatConvert<const void *, Pointer, std::enable_if_t<std::is_pointer_v<Pointer> && !std::is_array_v<std::remove_pointer_t<Pointer>> && !std::is_same_v<std::remove_pointer_t<Pointer>, char>>> : ImplicitConversion<const void *, const Pointer *> {};
 
 template<typename Pointer>
-struct FormatConvert<const void *, Pointer, std::enable_if_t<std::is_pointer_v<Pointer> && std::is_array_v<std::remove_pointer_t<Pointer>>>>
-{
-	static constexpr const void *convert(const Pointer pointer)
-	{
-		return pointer;
-	}
-};
+struct FormatConvert<const void *, Pointer, std::enable_if_t<std::is_pointer_v<Pointer> && std::is_array_v<std::remove_pointer_t<Pointer>>>> : ImplicitConversion<const void*, const Pointer> {};
 
 template<typename From, typename Enable = void>
 struct AutoConversion
@@ -99,50 +66,29 @@ struct AutoConversion
 	}
 };
 
-template<typename From>
-struct AutoConversion<From, std::enable_if_t<std::is_integral_v<From> && std::is_unsigned_v<From>>>
+template<char Conversion, typename From>
+struct SimpleAutoConversion
 {
 	static std::string conversion(const From &)
 	{
-		return "u";
+		return std::string{Conversion};
 	}
 };
 
 template<typename From>
-struct AutoConversion<From, std::enable_if_t<std::is_integral_v<From> && std::is_signed_v<From>>>
-{
-	static std::string conversion(const From &)
-	{
-		return "d";
-	}
-};
+struct AutoConversion<From, std::enable_if_t<std::is_integral_v<From> && std::is_unsigned_v<From>>> : SimpleAutoConversion<'u', From> {};
 
 template<typename From>
-struct AutoConversion<From, std::enable_if_t<std::is_convertible_v<From, double> && !std::is_integral_v<From>>>
-{
-	static std::string conversion(const From &)
-	{
-		return "G";
-	}
-};
+struct AutoConversion<From, std::enable_if_t<std::is_integral_v<From> && std::is_signed_v<From>>> : SimpleAutoConversion<'d', From> {};
 
 template<typename From>
-struct AutoConversion<From, std::enable_if_t<std::is_convertible_v<From, std::string_view>>>
-{
-	static std::string conversion(const From &)
-	{
-		return "s";
-	}
-};
+struct AutoConversion<From, std::enable_if_t<std::is_convertible_v<From, double> && !std::is_integral_v<From>>> : SimpleAutoConversion<'G', From> {};
+
+template<typename From>
+struct AutoConversion<From, std::enable_if_t<std::is_convertible_v<From, std::string_view>>> : SimpleAutoConversion<'s', From> {};
 
 template<>
-struct AutoConversion<char>
-{
-	static std::string conversion(const char)
-	{
-		return "c";
-	}
-};
+struct AutoConversion<char> : SimpleAutoConversion<'c', const char> {};
 
 namespace detail
 {