Added support for exception-free TOML; resolves #436 (#447)

Author: liuzicheng1987

include/rfl/toml/read.hpp

@@ -29,9 +29,21 @@ auto read(InputVarType _var) {
 /// Reads a TOML string.
 template <class T, class... Ps>
 Result<internal::wrap_in_rfl_array_t<T>> read(
-    const std::string_view _toml_str) {
-  auto table = ::toml::parse(_toml_str);
-  return read<T, Ps...>(&table);
+    const std::string_view _toml_str) noexcept {
+#if TOML_EXCEPTIONS
+  try {
+    auto table = ::toml::parse(_toml_str);
+    return read<T, Ps...>(&table);
+  } catch (const std::exception& e) {
+    return error(e.what());
+  }
+#else
+  auto result = ::toml::parse(_toml_str);
+  if (!result) {
+    return error(std::string(result.error().description()));
+  }
+  return read<T, Ps...>(&result.table());
+#endif
 }
 
 /// Parses an object from a stringstream.