Added a stringstream object to concatenate strings when building exception message

Operation.h

@@ -1,3 +1,5 @@
+#pragma once
+
 enum class OpType
 {
     Addition, Subtraction, Multiplication, Division, Modulo, Special

basecalc.h

@@ -1,3 +1,5 @@
+#pragma once
+
 #include "Operation.h"
 class BaseCalculator
 {

command.h

@@ -1,3 +1,5 @@
+#pragma once
+
 class Command
 {
     public:

input_resolver.cpp

@@ -1,6 +1,7 @@
 #include "input_resolver.h"
 #include <string>
 #include <iostream>
+#include <sstream>
 
 #define delimiter " "
 
@@ -63,7 +64,9 @@ Command resolveCommand()
     auto validation_result = validate_token(token);
     if (!validation_result.ok())
     {
-        throw std::runtime_error{"invalid token " + validation_result.incorrect_token()};
+        std::ostringstream os;
+        os << "invalid token "<< validation_result.incorrect_token();
+        throw std::runtime_error{os.str()};
     }
 
     bool shouldQuit = token.find("q") != token.npos;

input_resolver.h

@@ -1,2 +1,4 @@
+#pragma once
+
 #include "command.h"
 Command resolveCommand();

special_calculator.h

@@ -1,3 +1,5 @@
+#pragma once
+
 #include "basecalc.h"
 
 class SpecialCalculator: public BaseCalculator