Use Cpp::GetLanguageStandard to get language standard

Author: mcbarton

notebooks/tinyraytracer.ipynb

@@ -10,7 +10,7 @@
       "file_extension": ".cpp",
       "mimetype": "text/x-c++src",
       "name": "C++",
-      "version": "23"
+      "version": "cxx23"
     }
   },
   "nbformat_minor": 5,

notebooks/xeus-cpp-lite-demo.ipynb

@@ -10,7 +10,7 @@
       "file_extension": ".cpp",
       "mimetype": "text/x-c++src",
       "name": "C++",
-      "version": "23"
+      "version": "cxx23"
     }
   },
   "nbformat_minor": 5,

notebooks/xeus-cpp.ipynb

@@ -886,7 +886,7 @@
    "file_extension": ".cpp",
    "mimetype": "text/x-c++src",
    "name": "C++",
-   "version": "20"
+   "version": "cxx20"
   }
  },
  "nbformat": 4,

src/xinterpreter.cpp

@@ -75,33 +75,38 @@ namespace xcpp
         xeus::register_interpreter(this);
     }
 
+    // FIXME: This function should be upstreamed to CppInterOp. See
+    // https://github.com/compiler-research/CppInterOp/issues/879
     static std::string get_stdopt()
     {
-        // We need to find what's the C++ version the interpreter runs with.
-        const char* code = R"(
-int __get_cxx_version () {
-#if __cplusplus > 202302L
-    return 26;
-#elif __cplusplus > 202002L
-    return 23;
-#elif __cplusplus >  201703L
-    return 20;
-#elif __cplusplus > 201402L
-    return 17;
-#elif __cplusplus > 201103L || (defined(_WIN32) && _MSC_VER >= 1900)
-    return 14;
-#elif __cplusplus >= 201103L
-   return 11;
-#else
-  return 0;
-#endif
-  }
-__get_cxx_version ()
-      )";
-        auto cxx_version = Cpp::Evaluate(code);
-        return std::to_string(cxx_version);
-    }
+        switch (Cpp::GetLanguageStandard(nullptr))
+        {
+            case Cpp::InterpreterLanguageStandard::c11:
+                return "c11";
+            case Cpp::InterpreterLanguageStandard::c17:
+                return "c17";
+            case Cpp::InterpreterLanguageStandard::c23:
+                return "c23";
+            case Cpp::InterpreterLanguageStandard::c2y:
+                return "c2y";
+            case Cpp::InterpreterLanguageStandard::cxx11:
+                return "cxx11";
+            case Cpp::InterpreterLanguageStandard::cxx14:
+                return "cxx14";
+            case Cpp::InterpreterLanguageStandard::cxx17:
+                return "cxx17";
+            case Cpp::InterpreterLanguageStandard::cxx20:
+                return "cxx20";
+            case Cpp::InterpreterLanguageStandard::cxx23:
+                return "cxx23";
+            case Cpp::InterpreterLanguageStandard::cxx26:
+                return "cxx26";
+            case Cpp::InterpreterLanguageStandard::lang_unspecified:
+                return "lang_unspecified";
+        }
 
+        return "unknown";
+    }
     interpreter::interpreter(int argc, const char* const* argv) :
         xmagics()
         , p_cout_strbuf(nullptr)

test/test_interpreter.cpp

@@ -407,7 +407,7 @@ TEST_SUITE("kernel_info_request")
         REQUIRE(result["language_info"]["mimetype"] == "text/x-c++src");
         REQUIRE(result["language_info"]["codemirror_mode"] == "text/x-c++src");
         REQUIRE(result["language_info"]["file_extension"] == ".cpp");
-        REQUIRE(result["language_info"]["version"] == "23");
+        REQUIRE(result["language_info"]["version"] == "cxx23");
         REQUIRE(result["status"] == "ok");
     }