update arithmetic operator overloads for ArgumentValueList so that the rest of the list is copied to the resultant list. other small changes to resolve WSL compilation errors

Author: jemarq04

argparse.cpp

@@ -110,7 +110,8 @@ bool ArgumentValueList::operator<=(const char* other) const{
 
 // Arithmetic Operators {{{2
 ArgumentValueList ArgumentValueList::operator+(const char* other) const{
-	ArgumentValueList temp = {(std::string)at(0).c_str() + other};
+	ArgumentValueList temp = vec();
+	temp.at(0) = at(0) + other;
 	return temp;
 }
 

argparse.h

@@ -1,6 +1,6 @@
 #ifndef ARGPARSE_H
 #define ARGPARSE_H
-#define ARGPARSE_VERSION 2.2.6
+#define ARGPARSE_VERSION 2.2.7
 #include <iostream>
 #include <sstream>
 #include <fstream>
@@ -224,31 +224,31 @@ namespace argparse{
 		// Arithmetic Operators
 		template <typename T>
 		ArgumentValueList operator+(const T& other) const{
-			ArgumentValueList temp = {""};
+			ArgumentValueList temp = vec();
 			temp.at(0) = (T)at(0) + other;
 			return temp;
 		}
 		template <typename T>
 		ArgumentValueList operator-(const T& other) const{
-			ArgumentValueList temp = {""};
+			ArgumentValueList temp = vec();
 			temp.at(0) = (T)at(0) - other;
 			return temp;
 		}
 		template <typename T>
 		ArgumentValueList operator*(const T& other) const{
-			ArgumentValueList temp = {""};
+			ArgumentValueList temp = vec();
 			temp.at(0) = (T)at(0) * other;
 			return temp;
 		}
 		template <typename T>
 		ArgumentValueList operator/(const T& other) const{
-			ArgumentValueList temp = {""};
+			ArgumentValueList temp = vec();
 			temp.at(0) = (T)at(0) / other;
 			return temp;
 		}
 		template <typename T>
 		ArgumentValueList operator%(const T& other) const{
-			ArgumentValueList temp = {""};
+			ArgumentValueList temp = vec();
 			temp.at(0) = (T)at(0) % other;
 			return temp;
 		}