validation.h: Add always-strict AnswerValidator : Validator

headers/validation.h

@@ -1469,3 +1469,11 @@ class OutputValidator : public Validator {
 		return false;
 	}
 };
+
+class AnswerValidator : public Validator {
+  public:
+	// An OutputValidator can be run in different modes.
+	explicit AnswerValidator(int argc, char** argv, std::istream& in_ = std::cin)
+	    : Validator(/*ws_sensitive=*/true, /*space sensitive*/ true, in_,
+	                get_constraints_file(argc, argv)) {}
+};

test/problems/identity/answer_validators/answer_validator/output_validator.cpp

@@ -1,7 +1,7 @@
 #include "validation.h"
 
 int main(int argc, char** argv) {
-	OutputValidator v(argc, argv);
+	AnswerValidator v(argc, argv);
 	int answer = v.read_integer("answer", 0, 1000);
 	v.newline();
 }