Add big float extraction test

test/test_extractions.cpp

@@ -63,6 +63,11 @@ TEST_CASE("extract test functions for numbers with invalid inputs") {
     // random input for float
     CHECK_INVALID_CONVERSION("xxx1", float);
 
+    // number too big
+    CHECK_INVALID_CONVERSION((std::string{20, '1'} + "." +
+                              std::string{20, '2'}),
+                             double);
+
     // random input for int
     CHECK_INVALID_CONVERSION("xxx1", int);