add parse and stringify

src/yycc/macro/feature_probe.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+// Hint for C++ feature detection:
+// __cplusplus macro need special compiler switch enabled when compiling.
+// So we use _MSVC_LANG check it instead.
+
+// Detect C++ 20
+#if __cplusplus >= 202002L || (defined(_MSVC_LANG) && _MSVC_LANG >= 202002L)
+    #define YYCC_CPPFEAT_GE_CPP20
+#endif
+
+// Detect C++ 23
+#if __cplusplus >= 202302L || (defined(_MSVC_LANG) && _MSVC_LANG >= 202302L)
+    #define YYCC_CPPFEAT_GE_CPP23
+#endif
+
+// Check whether there is support of `contains` for `set` and `map` including their varients.
+#if defined(YYCC_CPPFEAT_GE_CPP20)
+    #define YYCC_CPPFEAT_CONTAINS
+#endif
+
+// Check whether there is support of `starts_with` and `ends_with` for `basic_string`.
+#if defined(__cpp_lib_starts_ends_with) || defined(YYCC_CPPFEAT_GE_CPP20)
+    #define YYCC_CPPTEST_STARTS_ENDS_WITH
+#endif
+
+// Check whether there is support of `std::expected`.
+#if defined(__cpp_lib_expected) || defined(YYCC_CPPFEAT_GE_CPP23)
+    #define YYCC_CPPTEST_EXPECTED
+#endif